MAPK3 and Ascites: This study extends our previous findings that ascites-induced activation of the Akt pathway attenuates TRAIL-induced apoptosis[13,17] by showing that ERK1/2/Elk-1 signaling is responsible for the transcriptional increase of Mcl-1, which in turn contributes to ascites-mediated inhibition of TRAIL-induced apoptosis in OC cells.