SOX2 and gastric cancer: Gastric cancers with induced CDX2 mRNA expression (independent of SOX2 expression) showed significantly lower expression of Human Leukocyte Antigen (HLA) class II proteins HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DQB1, and HLA-DRA (Student’s t test with p < 0.0001 for all comparisons) compared with gastric cancers with maintained CDX2 suppression, while HLA class I proteins HLA-A, HLA-B, and HLA-C displaced smaller differences between the groups (Figure 6A).