TGF-beta1 maintains homeostasis of rapidly proliferating cells, therefore is a potential tumor suppressor of non-malignant cells. Malignant transformation alters TGF-beta1 signalling pathway, turning it into a stimulator of tumor progression. We describe the case of 54 year old renal transplant patient with highly increased plasma TGF-beta1 level and planoepithelial carcinoma originating from parotid salivary gland. We discuss the role of TGF-beta1 in promotion of carcinogenesis and probable utility in prognosis of malignancy.