<s>[INST] brother in law had bone marrow transplant in aug. still in denver hosp but has developed ebs. with a know in the groin . going to have pet scan tomorrow. they had told him he had gone longer then some people w/o developing something. what can you tell me about how serious this is. i feel like the good progress he had made is turning. without knowing more to tell you i am just looking for something positive. [/INST] Hi, Thank you for posting your query. Unfortunately your query does not give out most of the details, which could enable us to give you a good answer. What do you mean by EBS? Generally, after bone marrow transplant, patients are more prone to develop infections, as their immunity is lowered due to use of immunosuppressant Chat Doctor. If you can upload some more details, it would be helpful. I hope it helps. Please get back if you require any additional information. Wishing you good health, </s>