SERPINE1 and neoplasm: In addition to YAP1, which has been linked to the formation of cancer-associated fibroblasts (CAFs)57 (as well as EMT58–60 and angiogenesis61), C2 tumours display increased expression of the CAF marker genes FAP and SERPINE1 (also known as PAI-1)62; the latter evidenced at both mRNA and protein levels (Supplementary Data 3, Fig. 5b).