CD274 and Alzheimer disease: The PD-L1 positive prevalence on TC was significantly higher in SCC than in AD when using ≥5% as a cut off (49.6% vs 36.5%, p = 0.0304) or marginally significantly higher when using ≥ 25% (29.5% vs. 19.2%, p = 0.0509) as a cut off.