COL4A1 and gastric cancer: One kind of GC cells (MKN-45 cells) was selected, and short hairpin RNAs (sh-RNA) specific to COL4A1 (sh-COL4A1) were transfected into MKN-45 cells to see the effects of COL4A1 silence on cell invasion, migration, EMT and Hedgehog signaling pathway.