(Neuron 97, 1284–1298; March 21, 2018) In the original article, individual numerical values in Table 3 were off by one row and three other values were mistyped. Several summary values were recalculated accordingly. These changes do not alter any conclusions of the manuscript. Consequently, values in several figures were incorrect. The correct values are as follows: Figure 4F, r = 0.45, p = 0.04; Figure 4G, r = 0.03, p = 0.87; Figure S8G, r = 0.43, p = 0.057. Under the Results section subheading “Tau Production Positively Correlates with Amyloidosis,” we had incorrectly stated amyloid positive in place of negative and negative in place of positive. The correct statements, also accounting for the correction to Table 3, should be as follows: “The tau FTRs from the amyloid-negative and -positive cohort are 0.0244 ± 0.0045 pools/day and 0.0221 ± 0.0028 pools/day, respectively (the average is 0.0231 ± 0.039 pools/day). The estimated tau half-lives in amyloid-negative and -positive cohorts are t1/2 = 29.4 ± 6.0 days and 31.5 ± 4.0 days, respectively (the average is t1/2 = 30.7 ± 5.1 days).” and “The estimated tau production rates from amyloid-negative and -positive cohorts are 22.9 ± 7.2 pg/mL/day and 27.8 ± 7.0 pg/mL/day, respectively (the average is 24.7 ± 7.3 pg/mL/day).” In the Key Resources Table, the reference for the Tau5 mouse monoclonal antibody was incorrect. The correct reference is LoPresti, P., Szuchet, S., Papasozomenos, S.C., Zinkowski, R.P., and Binder, L.I. (1995). Functional implications for the microtubule-associated protein tau: localization in oligodendrocytes. Proc. Natl. Acad. Sci. USA 92, 10369–10373. These errors have now been corrected in the paper online.