A new computational method for quantifying copy-number aberrations (CNAs) and whole-genome duplications (WGDs) in bulk tumor sequencing data is presented in Nature Communications this week. Developed by scientists from Princeton University, the approach — called holistic allele-specific tumor copy number heterogeneity, or HATCHet — is designed to infer allele- and clone-specific CNAs and WGDs jointly across multiple tumor samples from the same patient.