MAPK14 and esophageal squamous cell carcinoma: To assess the possible effects of MAPK on the regulation of DNMT1, HDAC2, and p16 expression by PAR4, ESCC cells were treated with PAR4-AP for 2 h and pretreated with U-46619 (ERK1/2 and p38 activator), tBHQ (ERK1/2 activator), PD98059 (ERK1/2 inhibitor), or SB203580 (p38 inhibitor) for 60 min.