MelRM and SKMel28 cells, known to be IFN-γ inducible for PD-L1 expression [25] as well as NM176 melanoma cells without previously reported data regarding PD-L1 inducibility, were spiked into healthy donor blood and recovered using the melanoma CTC isolation protocol after room temperature storage for 0, 24 or 48 hours. This evidence concerns the gene CD274 and melanoma.