And a study using the Tetraodon nigroviridis fish model proved that IL-16 can induce colitis by upregulating the expression of peptide transporter 1 (PepT1) in the colon, thereby increasing formyl-methionyl-leucyl-phenylalanine (fMLF) transport, thus triggering downstream inflammatory pathways (20). The gene discussed is IL16; the disease is colitis.