P2RX7 and infection: However, among the four voltage-gated and seven receptor-gated calcium channels tested, only P2X7, a receptor-gated calcium channel, was detectable in both J774A.1 and THP-1 cells by Western Blot assay (Figure 2A), This result indicates that P2X7 is the unique calcium channel expressed by J774A.1 and THP-1 cells, and receptor-gated calcium channel blockers, such as SKF96365 [46], could be used to determine extracellular Ca2+ influx through the P2X7 calcium channel in J774A.1 or THP-1 cells during infection.