MAPK3 and systemic lupus erythematosus: As shown in Figure 6, the phosphorylation of ERK1/2 (n = 3, P = 0.03) and SAPK/JNK (n = 3, P = 0.03) were higher in BMMSCs from SLE patients, as compared with normal controls (n = 4), while the phosphorylation of P38 showed similar levels in BMMSCs between SLE patients and normal controls, suggesting a partially activated MAPK pathway in BMMSCs from SLE patients.