P2RX4 and COVID-19: Another study showed that expression levels of P2X4 in myeloid cells were higher in males than in females, with potentially important consequences for several pathologies; eosinophils were by far the cell type expressing the highest level of P2X4 on the cell surface, suggesting that ATP-dependent activation could be important in the eosinophil biology in the context of COVID-19 [95].