IL2 and cancer: Starting as monotherapy with IL-2 or IFN-α for several malignant diseases (i.e., advanced renal cell carcinoma, metastatic melanoma, AIDS-related Kaposi’s sarcoma, etc.), cancer immunotherapy has evolved into safer and more efficacious targeted therapy, immune checkpoint inhibitors, and anti-CD19 chimeric antigen receptor (CAR) T cell therapies [103].