CNV in the Cdkn2a/Cdkn2b tandem gene locus were small (maximum size range of 4–210 kb, S3 Fig) except for one tumour with an overlapping compound deletion, and one with a large amplification on chromosome 4 with the breakpoint within Cdkn2a. Deletions within the Ikzf1 and Pten loci were also small, ranging from less than 1 kb up to more than 200 kb, and included loss of proximal, terminal or internal regions of the genes, often with common breakpoint regions across multiple TL. This evidence concerns the gene PTEN and neoplasm.