Measles virus replicates in and destroys malignant cells without affecting healthy cells. The study aimed to evaluate the lives attenuated Measles virus vaccine against Iraqi patient derived breast cancer cells that have functional BRCA1 BRCA2 genes and compare its activity against international breast cancer MCF 7 and CAL 51 cell lines. ...The cytopathic effect of the measles virus was determined using an H E stain. Immunocytochemistry assay using specific anti H protein monoclonal antibody for measles virus in the virally infected cells. ...