Using the coefficients obtained by multivariate Cox analysis, the risk score of melanoma patients was calculated according to the following formula: risk score = (−0.097) × A2M + (−0.185) × NAMPT + (−0.123) × LIF + (−0.247) × EBI3 + (−0.170) × ERAP1. The gene discussed is LIF; the disease is melanoma.