Breast cancer is one of the most common cancerous tumors and one of the main causes after lung cancer that leads to death, and the most common type of breast cancer is adenocarcinoma and is usually detected either during the examination before symptoms appear or after the woman notices the presence of the tumor. Breast cancer is one of the most common diseases in Iraq recently. This study was designed to measure the level of interleukin-7 and its role in cancer, as well as to find out the Level of lipids (cholesterol, triglycerides, and high-density lipoproteins) in breast cancer women and compare them with the control group. The results showed a significant increase( P≤ 0.05) in the level of interleukin-7and high-density lipoprotein cholesterol (357.505±89.921µg\L, 104.383±20.865mg\dl) respectively among patients with breast cancer compared with the control group (150.705±39.559µg\L,114.782±14.139mg\dl) respectively, , and the results showed a significant decrease ( P≤ 0.05) in the level of cholesterol a and triglycerides in patients with breast cancer (104.383±20.865mg\dl , 110.388±18.180mg\dl) respectively compared with the control group(114.782±14.139mg\dl, 138.925±23.178mg\dl) respectively.