A, Low frequency focal amplification of the OVAL locus in endometrial cancer, but not 16 other TCGA cancers (see Figure S6 in File S1). B, 56% of focally amplified cases were of the serous subtype, compared to 21% overall (P = 0.025, Fisher’s exact test). C, OVAL RNA was strongly induced in a subset of tumors, and this coincided with focal amplification of the AXI region. ND, not detected. D, Average RNA-seq read density in the AXI region for tumors with marked focal amplification (n = 4) compared to remaining tumors (normalized read counts per 1000 nt segment). E, Similar to ovarian cancer, GSEA analysis revealed induction of P53 targets in OVAL amplified tumors.