IDO1 and cutaneous melanoma: To verify this assumption, we conducted Pearson’s correlation test with the expression of 11 immune receptors and found that, similar to other cancers (53, 54), the TIL load significantly correlates with TIGIT (r=0.503, p=0.05), IDO1 (r=0.545, p=0.037), LAG3 (r=0.589, p=0.023) and ADORA2A (r=0.589, p=0.037) in skin melanomas, irrespective of their mutation rate.