YY1 was also confirmed to inhibit the growth and metastasis of pancreatic cancer cells in vivo and in vitro.[5] However, in melanoma, the increase of YY1 promotes melanoma metastasis, and YY1 can promote the proliferation, cell cycle progression, migration and invasion of melanoma cells.[6] The molecular mechanism of the apparent contradictory effects of YY1 in tumors is still unclear, but it can be seen from the existing research results that this opposite regulatory state mainly depends on different tumor cell types. The gene discussed is YY1; the disease is pancreatic neoplasm.