The amplicon of CTCFL at chromosome 20q13.31–32 contains, in addition to CTCFL, genes: PCK1, PMEPA1 (also known as STAG1), ZBP1, BMP7, MIR4325, MTRNR2L3, RAE1, RBM38, SPO11, MIR4532, C20ORF85, and ANKRD60. All genes in the amplicon are amplified in a similar percentage of cases in different series, albeit in variable levels across cancers. This evidence concerns the gene STAG1 and cancer.