LRIG1 and breast cancer: We undertook the current study to establish a simple, precise, and sensitive droplet digital polymerase chain reaction (ddPCR) assay for the quantification of LRIG1 gene copy numbers in cells and tissues, and we applied this assay to investigate the frequency of unbalanced LRIG1 gene recombination events in breast cancer, determine the frequency of LRIG1 gains and losses in a well-characterized breast cancer cohort, and validate, or refute, the previous claim that LRIG1 loss can predict early and late relapses in breast cancer.