LOS ANGELES--(BUSINESS WIRE)--Response Genetics, Inc. (NASDAQ: RGDX) today announced that it has begun performing the MAGE-A3 gene expression screening assay for GlaxoSmithKline’s (GSK) Phase III clinical trial of the investigational MAGE-A3 Antigen-Specific Cancer Immunotherapeutic (ASCI) as adjuvant therapy in MAGE-A3 positive patients with stage IB, II or IIIA Non-Small Cell Lung Cancer (NSCLC). These assays will be performed in formalin-fixed paraffin-embedded tissue.