But the recruitment strategy of selecting loyal patients is likely to reduce this chance. Fourth, the compliance of insulin medication was not examined. In conclusion, no cancer signal with insulin glargine was found in this carefully characterized clinical cohort with diabetes. While our study is limited in size, we avoided potential for major distortions by implementing a new user, active comparator study design. Our study thus adds to the evidence that insulin glargine does not increase the risk for any cancer outcomes when compared with its main treatment alternative, NPH insulin. Chemotherapy is still the main clinical treatment for cancer. Most of the chemotherapeutic drugs induce serious multi-drug resistance and a series of side effects, e.g., fatigue, muscle and joint pain, impaired immune responses, anemia, neutropenia and thrombocytopenia. Therefore, searching for novel anti-tumor agents from natural products with fewer adverse effects is highly important. The use of medicinal mushrooms in the fight against cancer has been known for a very long time in Korea, China, Japan, Russia, USA and Crizotinib 877399-52-5 Canada. Mushrooms produce a variety of complex, lowmolecular-weight compounds with diverse chemical compositions, such as phenolic compounds, polyketides, triterpenoids and steroids. Many have shown direct beneficial effects on cancer development by interfering with specific transduction pathways. Mushroom Pyropolyporus fomentarius Teng, also called Fomes fomentarius, is a fungus of the Polyporaceae family that acts a parasite on beech and birch trees ; it has worldwide distribution. P. fomentarius has wideranging uses, including medicinal use. Many bioactive substances were isolated from the P. fomentarius petroleum ether fraction, such as b-sitosterol, 5a,8a-epidioxy-ergosta-6,22-dien-3bol, ergosta-7,22-dien-3b-ol, ergosta-7,22-dien-3-palmitate, Stearic acid, Palmitic acid, Ergosta-7,22-dien-3-one, ergosta7,22-dien-3-one, dimethyl acetal and sterols. However, there no studies have demonstrated its anti-tumor activities and the underlying mechanism. Many traditional herbal medicines have shown antiproliferative effects on the S180 cell line or cytotoxic activities on the S180-bearing mouse model, alone or combined with cyclophosphamide. The present work has demonstrated the significant anti-tumor activity of the PFPE both in vitro and in vivo. One of the anti-tumor activity chemotherapeutic targets is cytotoxicity. Most clinically used anti-tumor agents possess significant cytotoxic activity in cell culture systems. In our paper, PFPE was toxic to S180 cells at 240 and 480 mg/ml in time-dosedependent manners. However, at the concentration of 120 mg/ml, there was no proliferation inhibition effect with the prolonged incubation time. The dose response phenomenon and low dose stimulation have been previously reported for other drugs. The lower concentration might have other functions, such as anti-inflammation, anti-virus, etc., and the underlying mechanisms require further exploration. Moreover, PFPE had no or little cytotoxicity in HEK-293 cells. Thus, the present study suggests that PFPE has a potential application as a natural anti-tumor agent. Defects in apoptosis are the critical step in the resistance to therapy in many types of cancers. Thus, apoptotic pathways are relevant targets in cancer therapies. Previous studies have shown that apoptosis is an important mechanism through which various anticancer agents exert anticancer effects. In the present study, we aimed to determine whether apoptosis was induced in S180 cells along with the PFPE exposure. As evidenced by Annexin V-FITC/PI double staining, we found that the proportion of early and late apoptotic cells increased significantly after the PFPE treatment.