SPI1 and myeloid leukemia: Especially, a recent study demonstrated that USP22 deficiency leads to myeloid leukemia upon oncogenic KRAS activation through a PU.1 dependent mechanism [16]; and data of another recent study also showed that USP22 loss promotes colorectal cancer by elevating mTOR activity, indicating USP22 may function as a tumor suppressor in colorectal cancer [17].