A doctoral thesis at the University of Basra discusses (the relationship between pathogenic genes encoded by bacteria and colorectal cancer). A thesis at the College discussed (the relationship between the gene expression of the genes FadA, bft, CdtB, ClbQ, ClbB, PltB, ClbA, and PltA in bacteria and colorectal cancer). The thesis of researcher Ahmed Saadoun Khamis demonstrated the role of pathogenic bacterial species associated with colorectal cancer in tumor development. The thesis aims to detect and measure the level of gene expression of genes encoded by pathogenic bacteria and their relationship to the disease. The study concluded that there is high gene expression of several genes (FadA, bft, CdtB, ClbQ, ClbB, PltB, ClbA, and PltA) encoded by bacterial species associated with colorectal cancer patients. It also indicated the possibility of adopting molecular diagnosis to detect the disease using primers. Specifically, it concerns the pathogenic genes present within the tumor-forming environment. The study recommended the use of meta-genomic analysis technology to obtain a clearer picture and a broader understanding of the microbial community associated with the tumor. It also recommended conducting further studies on other groups of cancers and focusing on the role played by bacteria in this regard.