Knocking out LIF by CRISPR/Cas9 repressed sphere-forming ability of a mouse pancreatic cancer cell line, which were isolated from a FVB/n KrasLSL-G12D/+; Trp53flox/+; Ptf1a-Cre mouse10 (Fig. 3c). The gene discussed is PTF1A; the disease is familial pancreatic carcinoma.