PGD and infection: To determine the impact of PGD on GIST cells, we elevated PGD expression in GIST-T1S and GIST-882S cells, and repressed its expression in GIST-T1R and GIST-882R cells by lentivirus infection and verified the altered expression of PGD in these GIST cell lines by qRT-PCR and western blotting (Fig. 4a, b and Supplementary Fig. 3A, B).