The College of Science at the University of Basrah organized a seminar entitled (Cytological Study of Staphylococcus aureus Biofilm  Extract Effect on Tumour Cell Lines )MCF-7 and LNCaP) in Vitro   ) by the graduate student Iman Awad Bachay The study aims extract an extracellular polymeric substance with distinctive properties that can prevent the growth of cancer cells through its effect on the programmed death mechanism. The study included the use of breast cancer (MCF7) and prostate cancer (LNCaP) cell lines as models of cancer cells and cell lines. Vero cells as models of normal cells. The MTT toxicity test for the biofilm extract was performed on the cells, and then the stimulation of the programmed death mechanism of the morphological survivors was studied using hematoxylin and eosin stain, and acridine orange/ethidium bromide stain. In addition to studying the biochemistry of programmed cell death resulting from the effect of the extract, this was done by isolating RNA from cancer cell lines after treating them with EPS and converting it to cDNA and using quantitative polymerase chain reaction (qRT-PCR) to detect its effect on blood levels. Expression of apoptosis genes. The study recommended that in vivo tests be necessary to determine potential interactions between bacterial EPS and host immunity.