LAPTM4B and hepatocellular carcinoma: In conclusion, AP4 could promote HCC cell proliferation, migration and invasion via upregulating LAPTM4B gene transcription by binding to the LAPTM4B gene promoter; then, the overexpression of LAPTM4B inhibits phosphorylation of c‐myc resulting in its accumulation, which then upregulates AP4 expression (Fig. 6G).