Differential plating and overnight cultureRT-PCR (WT-1, GATA-4, GATA-1, GDNF, BMP4, SCF, FGF2, EGF, FSHR, AR and ABP) + ICC (WT-1, GDNF, SCF, BMP4, VIM, PCNA, and GATA-4). The gene discussed is GDNF; the disease is intrahepatic cholangiocarcinoma.