OSBPL2 and obesity due to melanocortin 4 receptor deficiency: (iii) Deletion of OSBPL2 increases the ubiquitylation levels of β-catenin, leads to a decrease in β-catenin in the cytoplasm, reversing the suppression of adipogenic genes in the nucleus, (iv) and triggering preadipocytes to mature into adipocytes, finally leading to obesity-related characteristics and metabolic disorders.