Demethylation of the Intron 1 CpG island with 5-azacytidine causes expression of WT1. Moreover, we discovered that hypoxia also leads to demethylation of the Intron 1 CpG island, expression of WT1 lncRNA, and expression of WT1 in both AML cell lines and in primary AML samples. Here, WT1 is linked to acute myeloid leukemia.