PD-L1 immunolabeling was consistently high in canine melanoma, as demonstrated in 95% of oral melanomas (19/20), with most presenting TPS higher than 49% (18/20) [4] and 100% among 17 melanomas (13 oral and 4 cutaneous), with the TPS ranging from 1–14% [59]. This evidence concerns the gene CD274 and melanoma.