In patients, although MHC class II-dependent antigen recognition is a consistent finding, it is worth noting that in some studies, the degree of impact on killing with MHC class II-blocking antibodies is partial (Oh et al., 2020), and that in other studies, functional studies were performed with target cells where MHC class II expression was enhanced or stabilized (Cachot et al., 2021), leaving open the possibility of some degree of bystander tumor killing in a non-MHC-restricted manner, which could be relevant in tumor cells lacking MHC class II. This evidence concerns the gene HLA-C and neoplasm.