In addition to a traditional case-control analysis, we investigate the ε4 association with CTE stage and semiquantitative and quantitative regional tau measures and dementia, investigate whether the associations are independent of AD pathology, present findings stratified by age, compare the relative associations of ε4 with duration of play among football players, and investigate ε4 duration of play interactions. The gene discussed is MAPT; the disease is Alzheimer disease.