P2RX7 and systemic sclerosis: However, both the percentage of P2X7-positive cells (46 ± 7 vs. 35 ± 6%, p = 0.023; Figure 1B) and, particularly, the total amount of the P2X7R expression was significantly higher in SSc than healthy fibroblasts, as demonstrated by the ~3-times higher values of mean fluorescence intensity (MFI; 6.5 ± 2.6 vs. 2.2 ± 0.3, p = 0.0087; Figure 1C).