Endogenous interleukin 1 (IL‐1) is a pro‐inflammatory cytokine that induces interleukin 6 (IL‐6) production in monocytes and macrophages and is elevated in COVID‐19 disease, MAS and other conditions such as severe chimerical antigen receptor T cell (CAR‐T)‐mediated cytokine release syndrome (CRS).4 Here, IL6 is linked to macrophage activation syndrome.