SPHK1 and COVID-19: Additionally, we included evaluations of expression of SK1, CERS2 and SK1/CERS2 ratio in additional lung sections from control autopsies that exhibited non-COVID-19 pneumonia and diffused alveolar damage from patients with non-COVID-19 related ARDS to determine if the alteration of the sphingolipid rheostat was specific to COVID-19.