Alber Aqil led this study with Betty Y. H. Huang, Pavlos Pavlidis and Rajiv C. McCoy. When sequencing reads coming from polymorphic duplications are mismapped, they can produce trans-eQTL signals that look convincing but are not real. Given how heavily the field leans on eQTL catalogs, the paper sets out where these artifacts come from and how to spot them.