NFKBIZ and neoplasm: In agreement with these results, immunofluorescence analysis confirmed a strong infiltration of CD45+ immune cells together with elevated CXCL9 expression in α-PD-1-treated control B16-F10 tumors, which was strongly inhibited by IκBζ overexpression, and derived from both tumor and infiltrating CD45+ immune cells (Fig. 6h).