MAPK3 and pulmonary emphysema: However, both the total amount of doubly phosphorylated ERK 1/2 (4159 RU (SD 1722) vs 853 RU (SD 422), p=0.001; a fivefold difference) and the proportion of total ERK1/2 that was doubly phosphorylated (23.5% (SD 9.2) vs 8.3% (SD 9.0), p=0.002; a threefold difference) was significantly higher in patients with histological evidence of emphysema compared with those with normal lung (table 1, figure 1B–E).