Interestingly, the clinical application of optical imaging techniques for evaluating the efficacy of cancer-targeted treatment has been explored using a diffuse optical tomography breast imaging system (DOTBIS).345 In a proof-of-principle study with seven postmenopausal women with early-stage breast cancer who received pre-surgical treatment with an AKT inhibitor (MK-2206) or an aromatase inhibitor (exemestane or letrozole), DOTBIS was performed on the tumor at baseline and post-therapy. The gene discussed is CYP19A1; the disease is breast carcinoma.