Margaux Hujoel’s paper on haplotype-informed CNV detection (HI-CNV; Hujoel et al. 2022 Cell) is now published — congratulations, Margaux! This work explores the phenotypic impact of rare copy number variation in the human genome, discovering many new ways in which genetic variation shapes human traits. The analyses were enabled by a new computational approach we developed that substantially increases CNV detection power in large cohorts by pooling information across individuals who share extended SNP haplotypes. We applied this approach to SNP-array genotyping probe intensity data from UK Biobank (N~500K), detecting ~6-fold more CNVs that previous analyses, and accounting for approximately half of all rare gene inactivation events produced by genomic structural variation. Subsequent CNV-phenotype association and fine-mapping analyses identified CNVs at 97 loci (~75% novel) influencing human quantitative traits, many with large effect sizes (>1 standard deviation). CNVs at several loci created long allelic series that further elucidated the roles of gene dosage and regulatory elements in shaping human complex traits. [ Broad news story ]