IMPDH2 and cancer: Accumulating evidence suggests that IMPDH2 is the predominant isoform of IMPDH, and increased IMPDH2 expression is associated with tumorigenesis, metastasis and recurrence in most cancers, including leukaemia [37], prostate cancer [38], ovarian cancer [39], non-small cell lung cancer [40], and triple-negative breast cancer [41].