MAPK1 and neoplasm: We determined the levels of phosphorylated ERK1/2 (p-ERK) (at Threonine 202 and/or Tyrosine 204 in ERK1 and Threonine 185 and/or Tyrosine 187 in ERK2) in the tumor extracts from all treatment groups, and found significantly higher levels of p-ERK in the tumors treated with gemcitabine than in the control tumors (p = 0.0004) (Figure 5).