PDCD1 and melanoma: BCR diversity and clonal expansion were predictive of response in melanoma patients treated with PD‐1 inhibitor or CTLA‐4 inhibitor or a combination of PD‐1 inhibitor and CTLA‐4 inhibitor.[78] Furthermore, an additional study showed that improved ICI response activity in melanoma was also correlated with the BCR diversity of plasmablasts.[105] A study by Arian et al reported that BCR signature predicted response rate and OS in melanoma patients treated with a PD‐1 inhibitor or a combination of PD‐1 and CTLA‐4 inhibitors.[128]