CD274 and anemia: As previously described for the PFS outcome, a multivariate features selection process was performed on data from 95 patients from ICSM without missing values for the set of variables reported in Supplementary Table S1 (29 and 39 death events within 6 and 12 months from the starting of the treatment, respectively, while 67 death events during the entire follow-up period) identified IHC PDL1, ECOG PS (binarized), anemia and NLR as the most informative subset of predictors of death.