Further studies should explain why pediatric patients with MIS-C have higher levels of SARS-CoV-2 spike IgG than children with severe COVID-19 [87]; excessive inflammatory response; profound lymphopenia; broken cytokine production, including interferon-gamma, interleukin-7, and interleukin-22; and T-cell exhaustion [88]. The gene discussed is IFNG; the disease is lymphopenia.