To enable cross-species comparison, we established and characterised TPC2 and TRPML1 KO cell lines in the human hepatocellular carcinoma line Hep3B, complementing our existing murine RIL-175 TPC2 KO model (13, 30) (Supplementary Figures S1A-C). Here, MCOLN1 is linked to hepatocellular carcinoma.