GDF15 and COVID-19: A Norwegian study measured levels of GDF-15 in 123 hospitalized patients with COVID-19 and found significantly higher concentrations among those with a primary endpoint of admission to the ICU or death during hospitalization (median, 4225 pg/mL; IQR, 3197–5972 versus median, 2187 pg/mL; IQR, 1344–3620; p < 0.001).