HCRT and cancer: Although the biological role of the interaction between HLA-DQA1 and HCRT in cancer remained unknown until recently, the HLA-DQA1 M99V SAP at the interaction interface between these two important proteins may affect binding to its partner (Fig. 4a), which was predicted as deleterious but was classified as ‘tolerated’ (non-deleterious) via the SIFT method.