MDK and liver cancer: The gradually up-regulated genes included Apoh, Ahsg, Alb, Kng2, Adh1 and Aldob, which are specific for hepatocyte function; whereas the genes that were decreased stepwise included Mdk that is highly expressed in mid-gestation [19], and Hhat (hedgehog acyltransferase) that is required for SHH signaling which is closely related to embryonic development, liver regeneration and liver cancer stem cells [20–23] (Fig. 3a-b and Additional file 1: Figure S5b).