Quercetin, a flavonoid found in fruits and vegetables, has been shown to have significant anti-cancer properties. Research has demonstrated that quercetin can induce programmed cell death (apoptosis) in cancer cells, as well as inhibit the growth and spread of cancer cells. Quercetin has been shown to be effective in treating a variety of cancers, including breast, prostate, colon, and lung cancer, by interfering with multiple cellular signaling pathways involved in cancer development and progression. Additionally, quercetin has been shown to enhance the effectiveness of chemotherapy and radiation therapy, making it a promising adjunct therapy for individuals with cancer.