MAPK3 and thoracic cancer: To further investigate the effect of STP or UCN-01 on MAPK ERK1/2 or Akt activation in cultured thoracic cancer cells, dose–response and time-course studies were performed on cells treated with STP (100–400 nM) or UCN-01 (250–1000 nM) and harvested at 1 or 24 h after the onset of drug exposure (Figure 2).