PSPH and cancer: To do this we retrovirally expressed TAZ or TAZ S89A and used RT–qPCR to measure expression of the YAP activity markers Ctgf, the zebrafish embryonal cancer stem cell gene Myf543 and Phgdh, Psat1 and Psph of the serine biosynthesis pathway, previously linked to remodelling of metabolism in cancer 44, 45 and induced by Yap in myoblasts 23 and Yap‐driven ERMS 13.