JAK1 and endometrial cancer: The 13 JAK1 mutant endometrial cancers showed significantly lower expression of TAP1 (2.1-fold, P<0.001), LMP7 (3.0-fold, P<0.001), and HLA class I (2.5-fold, P<0.001) in comparison to JAK1 wildtype endometrial cancers (Figure 2).