JAK2 and cancer: Notably, catalpol induced cancer cell death via induction of mitochondrial apoptosis pathways, regulation of the expression of specific microRNAs, modulation of Sirt1, Kras, RACK1, PARP, PI3K/Akt, Bcl-2, and STAT3/JAK2/Src signaling pathways, and inactivation of NF-kB and Smad 2/3 signaling pathways.