YAP1 and neoplasm: In contrast, in Apc mutant tumour cells, uniformly elevated Wnt signalling induces YAP, TEAD1/2/4, Sox9 and Myc expression throughout the tissue, enabling all cells to proliferate in an unlimited fashion in response to conditions that activate YAP, which include various stimuli such as DNA damage, mechanical stress or inflammatory signals (Thompson, 2020).