PDCD1 and neoplasm: In UV-associated AS, the presence of PD-1 positive cells in the tumor (≥ 10) correlated with better overall survival (median 20.6 ± 8.5 months for PD1 ≥ 10 versus 5.8 ± 2.1 months for PD1 < 10, p = 0.035).