TGIF2 and cancer: Interestingly, levels of miRNA-34a appear to follow a specific profile: while downregulated in several other cancer types [52,53,54] and in MGUS, miRNA-34a overexpression has been reported in active MM in association to the inhibition of cell proliferation, colony formation, and increased cancer stem cells (CSCs) apoptosis in vitro, via a mechanism that reduces the expression of the transforming growth interaction factor 2 (TGIF2) [41].