Many of these studies used xenograft model systems with cancer cells that are either overexpressing wild type or LATS-insensitive YAP or TAZ [78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93], or in which YAP or TAZ have been knocked down [79,84,85,90,94,95,96,97,98,99,100,101]. This evidence concerns the gene WWTR1 and cancer.