The Biodesix Lung Reflex® (BLR) includes the blood-based GeneStrat® Genomic and VeriStrat ® Proteomic Tests. The proteomic test generates results based on a serum profile generated using MALDI-ToF, while the genomic tests are based on ddPCR. The BLR test is commercially available and is intended for use in a centralized laboratory for patients previously diagnosed with Non-Small Cell Lung Cancer (NSCLC). We will report on factors critical to demonstrating the utility of these tests, including the reporting of results within 72 hours. In this study, we will describe the assay development process for blood-based ddPCR assays with a focus on the KRAS mutations and their emerging importance in NSCLC. Most significant are findings related to the prevalence of the KRAS variants in the US community setting, potential of the KRAS variants as targets of therapy, as well as prognostic markers of response to chemotherapy. The latter utility will be discussed in the context of pairing results from the ddPCR test for KRAS with those from the VeriStrat test.