CD8A and Merkel cell skin cancer: In univariate analysis, a significantly reduced MCC-specific survival was seen in patients with an ulcerated primary tumor (HR = 2.49; 95% CI= 1.18–5.25; p = 0.02), increased N:CD8 ratio (HR = 1.21; 95% CI= 1.06–1.37; p = 0.004) and nodal involvement (HR = 3.17; 95% CI = 1.47–6.81; p = 0.003).