The correlation between the concepts related to diseases co-occurring with AD and the exploring classes of drugs for repurposing to AD is illustrated in Figure . In addition to certain obvious correlations such as cancers (neoplasm) -anticancer agents and cardiovascular diseases -cardiovascular system agents, there are some worth mentioning: Dementia -hematological agents: Studies have implicated vascular disorders as risk factors for dementia. Biological and epidemiological evidence have been reported concerning the role of certain hematologic factors such as homocysteine, cholesterol, fatty acids, antioxidants, and C-reactive protein in dementia. Abnormal (low or high) levels of hemoglobin have been associated with an enhanced risk of dementia, including AD, which may be associated with differences in white matter integrity. Association has been reported between blood leukocyte counts and increased risk of AD. Diabetes -hormones: An imbalance in sex hormones has been identified as having a critical impact on type 2 diabetes. Androgens have a noteworthy sex-dimorphic association with type 2 diabetes, since hyperandrogenism in females and hypogonadism in males are risk factors for type 2 diabetes. Thus, treatments aimed at correcting these sex hormone imbalance may prevent the development of type 2 diabetes or help in its treatment. Inflammation -immunomodulators: Inflammation is a central part of autoimmune diseases, which are caused by dysregulation of the immune system, involving imbalance between pro-inflammatory vs. anti-inflammatory mediators. Neoplasm -immunomodulators: Immunotherapy is treatment that uses your body's own immune system to help fight cancer. Many immunotherapeutic agents operate by activating an efficient antitumor response or reversing tumor-mediated immunosuppression through modulation of significant regulatory pathways. 225