This region was very rarely co-amplified with HER2 in amplified cancers, yet in non-amplified cancers robustly had the same copy number as HER2. We optimized HER2 and EFTUD2 primer-probes with TaqMan chemistry labeled with FAM and VIC respectively, and optimized conditions for droplet digital PCR (Figure 1). The gene discussed is ERBB2; the disease is cancer.