PIM1 and breast cancer: Another study showed that overexpression of serine/threonine kinase (PIM1) induced EMT and BCSC properties; however, knockdown of PIM1 downregulated the expression of EMT-related transcription factors (Snail, TWIST) and mesenchymal marker N-cadherin (Gao et al. 2019), thereby clearly indicating the importance of EMT and BCSCs in synergistically promoting BC metastasis.