The melanocortin receptor family consists of five types, MC1R to MC5R, all of which are G protein-coupled receptors with seven transmembrane helical structures. These receptors are expressed in various cells and tissues, such as skin, adipose tissue, brain, and gastrointestinal tract. They participate in multiple biological processes by activating the cAMP signaling pathway, including regulating skin pigmentation, inflammatory responses, energy balance, and appetite control. MC1R is particularly associated with skin pigmentation and UV response, and its mutations are closely related to increased risk of skin cancer, hair color, and variations in skin type. Research on the gene expression specificity and mutations of melanocortin receptors is crucial for understanding related physiological functions and disease mechanisms.