MAPK4 and acute respiratory distress syndrome: However, massARRAY assay data showed that the CpG methylation level of MAPK4 promoter did not change significantly between control and ALI mice (Additional file 1: Fig. S4b and Fig. S5a, P > 0.05), indicating that DNA demethylation of MAPK4 promoter maybe not contribute to the up-regulation of MAPK4 in ALI.