MST1 and cancer: Initial studies in mammalian cell culture and in vitro indicated that the regulation of the pathway in mammals is comparable with that seen in the fly; overexpression of combinations of Mst1/2, Lats1/2 and Sav1 results in Yap phosphorylation (at Ser127) and nuclear exit, whereas depletion of Lats1/2 in some cancer cell lines inhibits Yap phosphorylation.