E2F6 and pancreatic adenocarcinoma: Evaluation of the mutual exclusion between the eight E2Fs genes in the TCGA PAAD cohort showed that there are co-expressed relationships between E2F1 and E2F2, E2F1 and E2F4, E2F2 and E2F4, E2F2 and E2F8, E2F3 and E2F5, E2F4 and E2F8 (P < 0.05), E2F2 with E2F3, six, seven and E2F6 with E2F7, eight are highly mutually exclusive but not statistically significant (P > 0.05), probably due to the small sample size (Figure 7C).