Evidence-based clinical practice guideline aims to optimize PD-L1 lung tumor testing The College of American Pathologists (CAP), in collaboration with five other societies, developed a draft evidence-based clinical practice guideline that aims to optimize PD-L1 testing for patients with non-small cell lung cancer (NSCLC) who are being considered for immunooncology therapy. The guideline, "PD-L1 Testing of Patients With Lung Cancer for Immunooncology Therapies," includes a draft summary of six recommendations, which is now available for an open comment period from March 31 to April 23, 2021. All stakeholders-;including pathologists, oncologists, hospital or laboratory managers, and patient advocacy group representatives-;are encouraged to review and submit feedback on these draft recommendations.