POU5F1 and cancer: Unique molecular features of the hFL-HCC tumour line (Fig. 7d) included high expression of AGR2 (ref. 22) and PCSK1 (ref. 23), both previously identified as markers of primary hFL-HCCs; DCLK1 (ref. 24); and KRT20 (ref. 25), found in endodermal cancers, particularly of intestine; POU5F1 (also known as OCT4) and KLF4/5, critical regulators of stemness26; and AHR, shown to trigger malignant transformation of HpSCs on binding to dioxins and related agonists27.