Immunohistochemistry (IHC) analysis of programmed death-ligand 1 (PD-L1) expression at baseline demonstrated that all 12 samples presented <1% of PD-L1 expression in cancer cells, while PD-L1 in immune cells varied from <1% in half of the samples, and up to 9% in the other half (Fig. 1D). The gene discussed is CD274; the disease is cancer.