Abstract: A compound represented by Formula 1, a stereoisomer thereof or a pharmaceutically acceptable salt thereof may be used for treating or preventing an autoimmune disease or a cancer. The autoimmune disease may be any one selected from the group consisting of inflammatory bowel disease, multiple sclerosis, graft-versus-host disease, asthma, atopy, psoriasis, rheumatoid arthritis, systemic lupus erythematous and type 1 diabetes. The cancer may be selected from the group consisting of colon cancer, melanoma, liver cancer, gliocytoma, ovarian cancer, colorectal cancer, head and neck cancer, bladder cancer, kidney cell cancer, stomach cancer, breast cancer, metastatic cancer, prostate cancer, gallbladder cancer, pancreatic cancer, blood cancer, skin cancer and lung cancer.