ATP2A2 and asthma: Example western blots showing total SERCA2 protein and β-actin in ASM cells derived from four asthma patients and three non-asthmatic donors are shown in Figure 2B. Densitometry of total SERCA2 immunoreactivity from western blots showed that there was no significant difference in SERCA2 protein expression in normal (n = 10) compared to asthma (n = 10) ASM cell donors (106 ± 7 and 107 ± 5, respectively; p = 0.90; Figure 2C).