JAK3 and obesity due to melanocortin 4 receptor deficiency: Our data showed that although, over the sessions, the flox control counterparts of IEC-Jak3-KO animals had retained the spatial cognition task, the IEC-specific deficiency of Jak3 nevertheless predisposed the animals not only toward HFD-led obesity-associated glycemic dysregulation but also to its comorbidity of significant deficiency in spatial cognition, particularly with respect to working memory, roaming memory, reward memory and errors committed before reaching a particular destination.