TNC and obesity due to melanocortin 4 receptor deficiency: It is also interesting to note that variants in genes MYO16 and TNC are not significant when tested for independent main effect (as reported in Table 6) but they are included in the interaction model as suggested by ATHENA (Fig. 12) which suggests that these variants might work in combination to affect the etiology of obesity but would not be identified otherwise in an additive model.