Receptor for TNFSF4/OX40L/GP34. Is a costimulatory molecule implicated in long-term T-cell immunity. (Microbial infection) Acts as a receptor for human herpesvirus 6B/HHV-6B. Interacts with TRAF2, TRAF3 and TRAF5. (Microbial infection) Interacts with Human herpesvirus 6B/HHV-6B gQ1:gQ2 proteins. The disease is caused by variants affecting the gene represented in this entry. Truncated N-terminus.