MAPK3 and neoplasm: The resulting clusters were described based on the ERK1/2 pathway as follows: tumors that are CTLA-4H/H−ERK1/2 (N = 193), representing the biological relevant group for our study where tumor cells over-express CTLA-4 and are activated-like tumor as shown by ERK1/2 enrichment pathway; CTLA-4H/L−ERK1/2 (N = 125), which probably do not express CTLA-4 at the membrane level; and two low CTLA-4 expression groups, CTLA-4L/H−ERK1/2 (N = 203) and CTLA-4L/L−ERK1/2 (N = 226) (Figure 3B).