MYLK and cancer: Ca2+/calmodulin-activated kinases, such as myosin light chain kinase (MLCK) and zipper-interacting protein kinase (ZIPK) (Goeckeler and Wysolmerski, 1995; Murata-Hori et al., 1999), also promote the phosphorylation of RLC on Ser19 and Thr18 (Fig. 1), and are increasingly promising therapeutic targets, especially for cancer treatment (Fu et al., 2015; Gu et al., 2006).