CA6 and breast cancer: Bigler et al. suggests that the protein expression of a receptor tyrosine kinase oncogene c-erbB-2 in saliva can be helpful to measure patient response to chemotherapy for treatment of breast cancer; Zhang et al. reports the de novo discovery and validation of eight mRNA biomarkers and one protein biomarker (carbonic anhydrase 6 (CA6) protein) for the noninvasive detection of breast cancer, drawing from two-dimensional difference gel electrophoresis, RT-qPCR, and protein immunoblot techniques [40,41].