IFNA2 and hairy cell leukemia: IFN-α has been approved by FDA for treatment of several malignancies including hairy cell leukemia, chronic myelogenous leukemia, follicular lymphomas, malignant melanoma, multiple myeloma, or renal cell carcinoma (106, 107) but displays also significant toxicity and side effects such as flu-like symptoms, anorexia, fatigue, depression.