FGF2 and obesity due to melanocortin 4 receptor deficiency: In fish, the stimulation of different cytokines including tlr-5, il-1β, nf-κb, and il-8, nod2, lyz, tnf-α, and il-10, play important roles in bacterial defense and immune response, while the intestinal secretory and absorptive, obesity-related genes aqp8, muc2.1, fgf2, and pomca are involved in regulation of the intestinal diseases and digestion functions (Gomez and Balcazar, 2008; Dotti et al., 2017; Udayangani et al., 2017; Arias-Jayo et al., 2018; Montalbano et al., 2018).