PDCD1 and hepatocellular carcinoma: As an example, pre-treatment serum IL6 can correlate with improved initial response to nivolumab in a phase II trial for advanced melanoma (measured by ORR) (Yamazaki et al, 2017), but IL6 can also predict for worse long-term outcome to PD-1/L1 inhibitors in NSCLC (measured by PFS) (Keegan et al, 2020) and to atezolizumab/bevacizumab in hepatocellular carcinoma (measured by PFS and OS) (Myojin et al, 2022).