KRT5 and neoplasm: In the total study population, patients with high CK5 or CK6 expression (defined as ≥ 50% of tumor cells positive) showed worse OS than patients with low or negative expression (CK5 median OS for the high positive cohort 11.93 vs. 22.57 months for negative and 13.90 for the low positive cohort, p = 0.012, Fig. 2a; CK6 median OS for the high positive cohort 10.12 vs. 23.38 for negative and 21.24 for the low positive cohort, p < 0.001, Fig. 2d).