MC5R and neoplasm: MC1 was characterized by high expression of tumor proliferation-related genes such as BPIBF1, RSPO2, and CLU, in which RSPO2 is also associated with stem cell self-renewal.21 MC2 exhibits elevated expression of NFATC2, which is related to cell cycle regulation.22 MC3 is primarily characterized by the expression of functional proteins, including PLA2G2A, which is involved in phospholipid metabolism, TIMP1, which is related to extracellular matrix remodeling, and ADIRF, which regulates adipocyte differentiation and metabolism.