LCN2 and isolated hyperferritinemia: Reported iron-associated observations in COVID-19 include anemia of inflammation, decrements in serum iron (i.e., hypoferremia), transferrin and transferrin saturation (TSAT), and increments in serum ferritin (i.e., hyperferritinemia), hepcidin, lipocalin-2, catalytic iron, and soluble transferrin receptor.