Overall, FYN plays a significant role in the pathogenesis of many cancers [195] and varying degrees of evidence link FYN with hepatocellular carcinoma [196], oral cancer [193], mesothelioma [194], breast cancer [197], chronic myelogenous leukemia [198,199], prostate cancer [191,192], melanoma [200], brain cancer [190], and esophageal squamous cell carcinoma [201]. This evidence concerns the gene FYN and breast cancer.