As PP2A is a major tumor suppressor regulating several signaling pathways [18,19,54], the inhibition of PP2A by SET has an overall oncogenic effect as it can activate oncogenic signaling such as AKT, ERK1/2, c-MYC and GSK3-β to promote the survival and progression of cancer cells, as we describe in the following paragraphs. Here, MAPK3 is linked to neoplasm.