JAG1 and breast carcinoma: Interestingly, some studies have shown that Jag1 promoter is hypomethylated in breast cancer cells.44 Also, Jag1 promoter has been found to be a target of histone demethylase KDM4C.45 Thus, additional studies are necessary to elucidate whether the aforementioned epigenetic modifications may also regulate Jag1 expression in human ICCs.