In a large retrospective analysis, myocarditis and pericarditis have been observed more in anti-PD- or anti-PDL-1 monoclonal antibodies relative to those treated with anti-CTLA-4 monotherapy, and this may be due to the increased use of anti-PD-1 or anti-PDL-1 regimens over anti-CTLA-4 monotherapy [4]. Here, CTLA4 is linked to pericarditis.