Recent work by Johannet et al. showed that baseline serum autoantibody signatures are predictive of severe irAEs (not limited to thyroiditis) with adjuvant anti-PD-1 and/or anti-CTLA-4 [42], which presents further evidence that preexistent subclinical autoimmunity may be at the root of various irAEs. Here, CTLA4 is linked to thyroiditis.