To further explore the functional significance of PLAGL2 in β‐catenin activation induced by miR‐378a‐3p downregulation in human HCC cells, we studied the effect of siRNA‐mediated PLAGL2 knockdown on β‐catenin signaling in SMMC‐7721‐antagomiR‐378a‐3p tumor cells. Here, PLAGL2 is linked to hepatocellular carcinoma.