Background and Aim: Hashimoto's thyroiditis (HT) is the most common autoimmune thyroid disease, characterised by the destruction of the thyroid gland due to the production of autoantibodies against thyroid peroxidase and thyroglobulin. Studies have shown the interaction between some genetic changes in the cell and environmental factors as one of the risk factors for the occurrence of HT. The aim of the present study was to investigate the relationship between the rs61764370 polymorphism in the KRAS gene and the risk of development of HT. Materials and Methods: 120 HT patients and 120 healthy controls who had been matched in regard to age and gender participated in this study. PCR-RFLP method was used to determine the genotypes. Results: The frequency rates of AA, AC and CC genotypes were 87.5%, 8.5% and 6.7% in the control group, and 93.3%, 5.3% and 0.8% in the patient group respectively. Our results showed that the frequency of CC genotype was significantly higher in the control group than that in the patient group (P≤0.05). Conclusion: Our results suggested the protective effect of the CC genotype and C allele of the rs61764370 polymorphism in the KRAS gene on the development of HT.

Background: Lung cancer is one of the most common cancers around the world, and a majorcause of death. The KRAS and NRAS genes could cause malfunction in signal transduction and cellcycle regulation. Materials and Methods: In this study, the expression level of KRAS and NRAS biomarkersamong 50 lung cancer patients in comparison with 50 normal individuals was investigated. TotalRNA from blood samples was extracted and the cDNA synthesized. The specific primers fordetection of markers were designed and the expression levels of KRAS and NRAS genes in thepresence GAPDH using the qRT-PCR method were quantitatively studied. Results: Quantitative comparison showed that KRAS and NRAS expression levels increasedsignificantly in lung cancer patients compared to the control population. Results showed aquantitative increase of KRAS and NRAS genes with an increase of 2/05 and 3/43 fold respectively, for lung cancer compared to normal samples. Conclusion: Based on current study results, we could quantitatively predict the expression level ofKRAS and NRAS genes in patients which could be used as a biomarker indicator during screeningof lung cancer samples. This could also be used as a noninvasive method for the screening of thepopulation for early detection to inhibit cancer.