Immunofluorescent staining of MDA- (scr) and MDA- (shTg2) tumors for the fibroblast activation marker αSMA revealed a decreased fraction of αSMA+ tissue in MDA- (shTg2) tumors compared to control tumors (Figure 5d–e), suggesting that knockdown of Tg2 reduced primary tumor fibroblast activation. The gene discussed is ACTA1; the disease is neoplasm.