We next investigated whether MCPyV-infection in NSCLC is associated with clinical outcomes in HPV-infected lung cancer patients. The prevalence of HPV-infection with MCPyV and non-MCPyV was 26.5% (9 of 34) and 12.9% (15 of 116), respectively (Table 2 and Supplementary Table S2). Among the 34 MCPyV-positive samples, HPV DNA sequences were detected in 6 (27.3%) of 22 ADs, in 2 (20%) of 10 SCCs and in 1 (50%) of 2 other NSCLC subtypes (Table 3). Among the 9 HPV-positive (with MCPyV) samples, eight were the high-risk type, namely, HPV-16; another high-risk type detected was HPV-33 (Table 2). Similarly, of 15 HPV-positive (with non-MCPyV) samples, HPV-16 (n=12) was the main type found, with the proportion of HPV-18 (n=3) being relatively small (Table 3 and Supplementary Table S2). There was no statistically significant difference in HPV DNA positivity between the MCPyV and non-MCPyV groups (P=0.06).