Orresponding to 2.23 of deaths worldwide. Malaria is more dangerous for women and children. It was stated in the World Health Organization’s 2011 World Malaria Report (http://www.who.int/malaria/world_malaria_report_2011/ 9789241564403_eng.pdf) that 81 of cases and 91 of deaths occurred in the African Region, mostly involving children underfive and women with pregnancy. Malaria was usually associated with poverty; actually it was a cause of 1485-00-3 biological activity poverty and a major hindrance for economic development. The situation has become even worse over the last few years with the increase in resistance to the drugs normally used to combat the parasites that cause the disease. 12926553 Therefore, one strategy to deal with the growing malaria problem is to identify and characterize new and durable antimalarial drug targets, the majority of which are FD&C Yellow 5 parasite proteins [1]. Parasite secretes an array of proteins within the host erythrocyte to facilitate its own survival within the host cell. These proteins can serve as potential drug or vaccine targets. However, it is difficult to experimentally identify the secretory proteins of P. falciparum owing to the complex nature of parasite. With the completion of Plasmodium genome sequence, it is both challenging and urgent to develop an automatic method or high throughput tool for identifying secretory proteins of P. falciparum. Actually, some efforts have been made in this regard. In a pioneer study, Verma et al. [2] proposed a method for identifying proteins secreted by malaria parasite. In their prediction method, the operation engine was the Support Vector Machine (SVM)Predicting Secretory Proteins of Malaria Parasitewhile the protein samples were formulated with the amino acid composition, dipeptide composition, 
and position specific scoring matrix (PSSM) [3]. Subsequently, Zuo and Li [4] introduced the K-minimum increment of diversity (K-MID) approach to predict secretory proteins of malaria parasite based on grouping of amino acids. Meanwhile, various studies around this topic were also carried out 23727046 [5,6,7,8,9]. In the past, various predictors for protein systems were developed by incorporating the evolutionary information via PSSM [10,11,12,13,14,15,16,17,18,19,20]. In the above papers, however, only the statistical information of PSSM [3] was utilized but the inner interactions among the constituent amino acid residues in a protein sample, or its sequence-order effects, were ignored. To avoid completely lose the sequence-order information associated with PSSM, the concept of pseudo amino acid composition (PseAAC) [21,22] was utilized to incorporate the evolutionary information into the formulation of a protein sample, as done in predicting protein subcellular localization [23,24,25], predicting protein fold pattern [26], identifying membrane proteins and their types [27], predicting enzyme functional classes and subclasses [28], identifying protein quaternary structural attribute [29], predicting antibacterial peptides [30], predicting allergenic proteins [31], and identifying proteases and their types [32]. The present study was initiated in an attempt to develop a new and more powerful predictor for 
identifying the secretory proteins of malaria parasite by incorporating the sequence evolution information into PseAAC via a grey system model [33]. According to a recent review [34], to establish a really useful statistical predictor for a protein system, we need to consider the following procedures: (i) construc.Orresponding to 2.23 of deaths worldwide. Malaria is more dangerous for women and children. It was stated in the World Health Organization’s 2011 World Malaria Report (http://www.who.int/malaria/world_malaria_report_2011/ 9789241564403_eng.pdf) that 81 of cases and 91 of deaths occurred in the African Region, mostly involving children underfive and women with pregnancy. Malaria was usually associated with poverty; actually it was a cause of poverty and a major hindrance for economic development. The situation has become even worse over the last few years with the increase in resistance to the drugs normally used to combat the parasites that cause the disease. 12926553 Therefore, one strategy to deal with the growing malaria problem is to identify and characterize new and durable antimalarial drug targets, the majority of which are parasite proteins [1]. Parasite secretes an array of proteins within the host erythrocyte to facilitate its own survival within the host cell. These proteins can serve as potential drug or vaccine targets. However, it is difficult to experimentally identify the secretory proteins of P. falciparum owing to the complex nature of parasite. With the completion of Plasmodium genome sequence, it is both challenging and urgent to develop an automatic method or high throughput tool for identifying secretory proteins of P. falciparum. Actually, some efforts have been made in this regard. In a pioneer study, Verma et al. [2] proposed a method for identifying proteins secreted by malaria parasite. In their prediction method, the operation engine was the Support Vector Machine (SVM)Predicting Secretory Proteins of Malaria Parasitewhile the protein samples were formulated with the amino acid composition, dipeptide composition, and position specific scoring matrix (PSSM) [3]. Subsequently, Zuo and Li [4] introduced the K-minimum increment of diversity (K-MID) approach to predict secretory proteins of malaria parasite based on grouping of amino acids. Meanwhile, various studies around this topic were also carried out 23727046 [5,6,7,8,9]. In the past, various predictors for protein systems were developed by incorporating the evolutionary information via PSSM [10,11,12,13,14,15,16,17,18,19,20]. In the above papers, however, only the statistical information of PSSM [3] was utilized but the inner interactions among the constituent amino acid residues in a protein sample, or its sequence-order effects, were ignored. To avoid completely lose the sequence-order information associated with PSSM, the concept of pseudo amino acid composition (PseAAC) [21,22] was utilized to incorporate the evolutionary information into the formulation of a protein sample, as done in predicting protein subcellular localization [23,24,25], predicting protein fold pattern [26], identifying membrane proteins and their types [27], predicting enzyme functional classes and subclasses [28], identifying protein quaternary structural attribute [29], predicting antibacterial peptides [30], predicting allergenic proteins [31], and identifying proteases and their types [32]. The present study was initiated in an attempt to develop a new and more powerful predictor for identifying the secretory proteins of malaria parasite by incorporating the sequence evolution information into PseAAC via a grey system model [33]. According to a recent review [34], to establish a really useful statistical predictor for a protein system, we need to consider the following procedures: (i) construc.