Molecular pathophysiology is a science that studies the etiology and pathogenesis of diseases of arising primary from the damage occurring in the cell or through the impairment of its subcellular and molecular formation. Molecular pathology is a relatively new science aiming at the discovery of the mechanisms underlying the pathology of the cell and its subcellular structures, elucidating the etiology of these changes, and examining those changes in dynamics. As the scientists were shedding more light on composition and the role of macromolecules, it became clear that it was at this level that the structure and function of the cells changed under the influence of unfavorable pathogenic factors. Impaired functioning of the cells can be due to numerous reasons. For example, the increased ionizing or ultraviolet radiation results in the changes of the enzymatic and molecular processes. Various diseases (cancer, for instance) are caused by mutations or alterations in the genetic code of a person, and identification of specific hallmark mutations allows pathologists to classify a disease and choose the appropriate treatment. Thus, molecular analysis leads the way towards personalized medicine by allowing health care providers to predict a patient’s response to certain anti-cancer therapy based on their own genetic make-up. Also, molecular pathology includes the development of molecular and genetic approaches to the diagnosis and classification of human tumors and also to design and validate predictive biomarkers for prognosis of the disease, and susceptibility of developing certain cancers in individuals.