Sung In Kyu,  former member of disbanded DSP Entertainment group A'st1, recently revealed that he was diagnosed with thymus cancer.  Thymus cancer occurs from tumors originating from the thymic epithelial cells.  Symptoms include difficulty swallowing, a strong cough, and/or chest pain.  Typically, surgery is required to remove the tumor and recover from the disease. On October 31st, he posted on his mini homepage,

I will confess. I don't like people calling a person sick. On April, 2011, severe chest pains began to start. I kept thinking it wasn't anything until May. I felt that the condition was serious and went to the hospital to take CT scans. They told me that there was a lump discovered in my chest and it continued to the veins on my neck I didn't think it would be serious, I was hospitalized and I had a biopsy examination and waited a few days. Before the results came out, they said it was one of the three things.. I found out that they weren't good things It was a tumor...and it was infectious...in one word, I didn't think it became a thymus cancer tumor as it went up to the veins on my neck, making it difficult to breathe. If I had waited any longer, it would have become something unimaginable Since last May, I had 6 chemotherapy sessions. Since surgery was dangerous, they said I couldn't do it... I thought I was healthy, but a sickness found me without a reason I'm really receiving a lot of stress and from the second half of 2009, I had a difficult time. I had a lot of concerns on everything...I have a rare disease, thymus gland cancer, 2nd stage. They said that it wasn't because something (ie one of his body parts) wasn't good. It seems the cause is stress, and they said it's good to not sing the songs I like in the hospital for now.  Now when I sing, even though it's hard to breathe, I won't give up my dream...I'll show you As I receive treatment, I will deliver good news. It seems I'm telling this all now and I thank all those who have waited for me and had me in their thoughts I will make sure to return it and I will see you on the stage. I love you.