Furthermore, while PD-L1 expression on tumor cells did not tend to be related to the response rate in melanoma patients treated with anti-PD-1 antibody (nivolumab) and anti-CTLA-4-antibody (ipilimumab), there was a correlation with a good response in non-small lung cancer patients treated with these drugs (6, 7). Here, CTLA4 is linked to neoplasm.