CD274 and melanoma: Although PD-L1v178, which was found in both pretreated and relapsed tumors in JFCR-119, was previously reported in several melanoma cell lines and suggested to be the origin of the circulating PD-L1 in serum (Zhou et al., 2017), in our investigation, PD-L1v178 was unstable and barely secreted and did not associate with the resistance to PD-L1 blockade therapy even though it lacked the transmembrane region.