8 y old male presented with fever, coughing, weight loss and severe fatigue. He had lymphopenia, raised CRP, troponins, d‐dimers, and IL6. ECG showed discrete ST elevation consistent with pericarditis, with MRI showing evidence of diffuse myocardial edema. He was admitted to PICU and treated with IV immunoglobulins and dobutamine. This evidence concerns the gene IL6 and lymphopenia.