Wheat is one of the most important cereal in today's diet that is used to make bread and many other foods and is a key source of food all over the world. The most important storage wheat protein, found exclusively in the starch of endosperm, is gluten - a mixture of gliadine and glutenine. These wheat components are extremely dangerous for people with gluten intolerance, or with diagnosed celiac disease. Celiac disease is a disease that affects about 1% of Western population. Despite the fact that are many diseases whch are known that are caused by gluten consumption in individuals, the association of glutenrelated consumption with cancer is still not clear. The aim of this paper was to investigate the antiproliferative effect of gluten and gliadine on the three selected tumor cell lines HCT-116, Caco-2 and SW620 and one cell line of HFF fibroblasts in in vitro conditions and analysis of possible differences in protein expression important for celiac disease (TGM2) and immune response (NFkB and RANKL). Low concentrations of gluten and gliadine with low concentrations of ethanol in the solution acted proliferatively on all tested cells and the effect of ethanol at higher concentrations showed antiproliferative effect on the cells. Also, minor changes in levels of TGM2, NfκB and RANKL levels were observed after gluten and gliadine treatment, which more closely followed the effects of treatment with the corresponding ethanol controls. Only gliadine induced a statistically significant decrease in NfκB levels after 24h treatment in HCT-116 cells that could be distinguished from the effect of the associated ethanol control.