Figure 1.

Plots (a‐f) depict the presence or the absence of loss of heterozygosity (LOH) in each tumor across the first 80 million bases of chromosome 2, which encompasses the MSH2 gene. Samples 31001, 44001, 67001, 10101, 00011 show minimal LOH across this region, while 04001 demonstrates substantial evidence for LOH. Plot (g) shows MSH2 and the immediately surrounding region in 04001, which demonstrates that a large proportion of the gene is affected by LOH, including the reported germline heterozygous mutation at c.2131