FSTL3 and primary peritoneal carcinoma: In contrast, overexpression of FSTL3 caused resistance to PPC in our KPCA.FSTKO_hFSTL3 model (Fig. 3H), indicating that overexpression of FSTL3 phenocopies FST-mediated resistance to PPC, which failed to significantly improve overall survival, albeit leading to slightly smaller tumors at endpoint (F ig.