APC and neoplasm: Our blood sample from week 2 revealed the KRAS mutation and four more major tumour mutations in the following genes (see Table 1): APC (in 49% of sequences), TP53 (39%), KRAS (32%), THSD7B (20%), and a copy number amplification of a chromosomal segment on chromosome 4 containing FBXW7. The copy number amplification was deduced from a genomic stretch of germline polymorphisms with near-identical allele frequencies of around 0.25 (see Additional file 1: Table S1) instead of the expected allele frequency of 0.50.