ENPP2 and COVID-19: Interestingly, components of the COVID-19 cytokine storm (IL-6, TNF, and IL-1β) have been suggested to stimulate ATX expression and/or activity in different cell types, while, vice versa, LPA has been reported to stimulate TNF and IL-6 expression in different contexts [22], suggesting a possible interplay of the COVID-19 cytokine storm and the ATX/LPA axis.