Moreover, it has been suggested that activated inflammatory IkappaB kinase β–nuclear factor kappa B (IKKβ–NFκB) signaling and increased expression of pro-inflammatory factors including tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 β (IL-1β) contributed to olanzapine-induced obesity (Zhang et al., 2014a; He et al., 2019). Here, IL6 is linked to obesity due to melanocortin 4 receptor deficiency.