Pin1 is upregulated in malignant tumors, hepatitis, and metabolic syndrome-related diseases such as obesity and diabetes and has been reported to be involved in promoting the pathogenesis of these diseases (Liou et al., 2003; Rustighi et al., 2017; Inoue et al., 2019). This evidence concerns the gene PIN1 and obesity due to melanocortin 4 receptor deficiency.