Heatmap showing allele frequencies of variants found to be biallelic in at least one sample of eight prostate cancers with sequencing of matched primary and metastases (A10-A34, different sites indicated as in Gundem et al.12). Early clonal biallelic mutations are detected in all samples of a patient (e.g., A10 chr19:29,339,579), while late clonal and subclonal ones show no evidence of being biallelic in some samples (beta-binomial p-value > 0.05 and no discordant phasing to a heterozygous germline SNP) or are detected in only a subset of samples (e.g., A22 chr14:61,497,015 and A10 chr2:117,463,664, respectively).