Furthermore, a pre-clinical study with poorly immunogenic sarcoma lines where either MHC class I- or MHC class II-restricted neoantigens were expressed demonstrated that recognition of MHC class II-dependent neoantigens on tumor cells by CD4+ T cells was necessary for tumor rejection in response to checkpoint inhibition and collaborated with MHC class I-dependent neoantigen recognition by CD8+ T cells in this context (Alspach et al., 2019). The gene discussed is CD4; the disease is sarcoma.