Down-regulation of both HDAC3 and HDAC7 up-regulated ATX expression in the cancer cells with low ATX expression, while over-expression of HDAC7 inhibited ATX expression in a HDAC3-dependent manner in the cancer cells with high endogenous ATX expression, indicating that HDAC3 and HDAC7 collaboratively suppress ATX expression in cancer cells. The gene discussed is ENPP2; the disease is cancer.