CD274 and neoplasm: The European Larynx Organ Preservation Study (ELOS) (1) is a prospective, randomized, open-label, two-armed parallel group controlled, phase II multicenter larynx organ preservation (LOP) trial in locoregionally advanced (LA) stage III, IVA/B squamous cell carcinoma of the larynx or hypopharynx (LHSCC) with PD-L1 expression within tumor tissue biopsy, calculated as CPS ≥ 1, amenable for total laryngectomy (TL).