RT-qPCR results also suggested that the expression of PIK3CD-AS1 in HCC cells (HepG2, Hep3B, Huh7, SMMC-7721 and MHCC-97H) was significantly lower than that in human normal liver cell (L-O2) (all P < 0.05). The gene discussed is PIK3CD; the disease is hepatocellular carcinoma.