MELK and breast cancer: Further, Maternal Embryonic Leucine Zipper Kinase (MELK) is also a biomarker for radio-resistance, a study suggests that high expression of MELK in breast cancer tissues and TNBC, and expression of MELK is significantly associated with radioresistance [172] and inactivation of MELK (genetically and pharmacologically) increased radiation sensitivity in vitro and inhibits tumor growth in vivo [172].