Cytology is study of function and structure of cells whereas histology is the branch of science which deals with study of microscopic tissue structure. Both cytology and histological studies are applied to I diagnosis of infectious diseases, inflammatory diseases and autoimmune disease. Histology and Cytology studies also help in drug designing, enzyme study, cancer detection and many others.
Cell lines play a major role in testing and development of drugs, development of cell-based therapy, and research related to cancer tissues, among other applications. New drugs developed in pharmaceutical companies are safely and effectively tested on differentiated stem cells for checking their potential.