['Directly targeting therapeutic suicide gene to a solid tumor is a hopeful approach for cancer gene therapy. Treatment of a solid tumor by an effective vector for a suicide gene remains a challenge. Given the lack of effective treatments, we constructed a bifidobacterial recombinant thymidine kinase (BF-rTK) -ganciclovir (GCV) targeting system (BKV) to meet this requirement and to explore antitumor mechanisms.', 'Bifidobacterium (BF) or BF-rTK was injected intratumorally with or without ganciclovir in a human colo320 intestinal xenograft tumor model. The tumor tissues were analyzed using apoptosis antibody arrays, real time PCR and western blot. The colo320 cell was analyzed by the gene silencing method. Autophagy and necroptosis were also detected in colo320 cell. Meanwhile, three human digestive system xenograft tumor models (colorectal cancer colo320, gastric cancer MKN-45 and liver cancer SSMC-7721) and a breast cancer (MDA-MB-231) model were employed to validate the universality of BF-rTK\u2009+\u2009GCV in solid tumor gene therapy. The survival rate was evaluated in three human cancer models after the BF-rTK\u2009+\u2009GCV intratumor treatment. The analysis of inflammatory markers (TNF-α) in tumor indicated that BF-rTK\u2009+\u2009GCV significantly inhibited TNF-α expression.', 'The results suggested that BF-rTK\u2009+\u2009GCV induced tumor apoptosis without autophagy and necroptosis occurrence. The apoptosis was transduced by multiple signaling pathways mediated by FasL and TNFR2 and mainly activated the mitochondrial control of apoptosis via Bid and Bim, which was rescued by silencing Bid or/and Bim. However, BF\u2009+\u2009GCV only induced apoptosis via Fas/FasL signal pathway accompanied with increased P53 expression. We further found that BF-rTK\u2009+\u2009GCV inhibited the expression of the inflammatory maker of TNF-α. However, BF-rTK\u2009+\u2009GCV did not result in necroptosis and autophagy.'] Does bifidobacterial recombinant thymidine kinase-ganciclovir gene therapy system induce FasL and TNFR2 mediated antitumor apoptosis in solid tumors?