After announcing its intention to spin-off its preclinical activities in October 2011, Swedish biotech Karo Bio has formed a research collaboration with Pfizer to advance its ROR-gamma (retinoic acid-related orphan receptor gamma) drug discovery programme for autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and psoriasis. The deal, which is potentially worth up to US$217 M, highlights the attractiveness of ROR-gamma as a therapeutic target.