SEMA6D and gastric cancer: Comparison of Sema6D protein levels in SGC-7901 among three groups of human gastric cancer cells showed that Sema6D levels in the si-NC group were higher than those in the si-1 and si-2 groups after knockdown Sema6D, and Sema6D protein levels in the si-1 group were higher than those in the si-2 group.