Piper Jaffray analyst William Quirk names CareDx (CDNA), Illumina (ILMN) and Myriad Genetics (MYGN) his firm's top Diagnostics & Life Science Tools ideas for 2019. The analyst's top small cap idea is CareDx. He believes AlloSure volumes will continue to drive top line and bottom line leverage for the company in 2019. Quirk's top mid cap idea is Myriad. The analyst says the company "has multiple shots on goal" and that it will garner incremental reimbursement across several tests leading to upside in 2019. His top large cap idea is Illumina. Large population sequencing projects will accelerate beginning in 2019, which combined with eventual average risk NIPT expansion and ongoing "robust" oncology adoption, will continue generating upside to consensus expectations for the company, Quirk tells investors in a research note. The analyst keeps Overweight ratings on all three names.