CXCL5 and exanthem: The earliest that we expected severe nivolumab-induced irAEs (e.g., colitis, skin rash) might occur was 5∼6 weeks after initial administration [29], so we measured serum levels of sCD163 and CXCL5 (predictors of irAEs) at day 0 (to establish a baseline immediately before the administration of nivolumab and IFN-β) and at day 42, six weeks after the administration of nivolumab/IFN-β.