European Society of Human Genetics Jun 14 2026 Oral corticosteroids (OCSs) are widely used and effective in the treatment of chronic inflammatory conditions such as arthritis, asthma, and autoimmune diseases. They work by reducing inflammation, relieving pain, and calming the immune system. However, over one in ten patients develop side effects, particularly if they use steroids over a long period. Until now, it has been difficult to identify those who will react in this way, but results from