However, 100 uM dRYamide-fed Sk2 mutants' exhibit significantly higher levels of TG relative to 100 uM dRYamide-fed wt flies, suggesting that increased caloric intake through perturbation of dNepYr expression is not the only contributing factor to the obesity phenotype. Here, SPHK2 is linked to obesity due to melanocortin 4 receptor deficiency.