However, identifying patients most likely to benefit from immunotherapy is likely to be key for the success of future RCTs, as inflammation is unlikely to be relevant for all patients with depression.99 A RCT of infliximab for treatment resistant depression demonstrated treatment response to be associated with higher baseline CRP levels.100 A proof-of-concept double blind RCT of the anti-IL-6R mAb tocilizumab in patients with depression is underway, with subjects selected based upon evidence of inflammation and inflammation-related symptoms.101. Here, IL6R is linked to depressive disorder.