Conversely, some studies associated soluble PD-L1 levels in patient plasma with better response to immune checkpoint inhibitors, particularly to anti–PD-1 (aPD-1) and anti–CTLA-4 antibodies in patients with melanoma or multiple myeloma (Wang et al., 2015; Zhou et al., 2017). The gene discussed is PDCD1; the disease is plasma cell myeloma.