Its use has shown promising outcomes in influencing melanoma growth and metastasis through several mechanisms, such as induction of cell cycle arrest, inhibition of TRB3 expression, activation of AMPK, and potential synergy with other therapies like combining metformin alongside other immunotherapies, anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4) (ipilimumab) and anti-PD-1 (nivolumab), which are already approved for melanoma treatment [1]. Here, CTLA4 is linked to melanoma.