In an attempt to shed light on the observed difference in oncogenicity and tumor latency between PIK3CA E545K and H1047R, we performed comparative gene expression microarray analyses (using the Applied BiosystemsTM GeneChipTM Clariom S human array) of the stably transfected SNU387 and SNU449 HCC cell lines. Here, PIK3CA is linked to hepatocellular carcinoma.