First line of defense for pathogen recognition arisen with toll-like receptors TLR2, TLR4 and TLR5 in different infectious diseases such as malaria (adj pval 0.014), amoebiasis (adj pval 0.027) and legionellosis (adj pval 0.039) according to GEA over KEGG database. The gene discussed is TLR4; the disease is legionellosis.