FSTL1 and prostate cancer: On the other hand, increased expression of FSTL1 compared to healthy control tissue was observed in brain cancer cells [18], in fibroblasts but not in epithelial cells in colon tumours [59], in castration-recurrent prostate cancer [60], in most cases of hepatocellular carcinomas (HCC) [61], in head and neck squamous cell carcinoma (HNSCC) [62], and esophageal squamous cell carcinoma (ESCC) [63].