In this Letter, errors occurred in the following figures. In Extended Data Fig. 6e, the ‘shScr, Aged donor’ image is a duplicate of the ‘Vehicle, Aged donor’ image in Fig. 3f . The images in Extended Data Fig. 6e represent differences in engraftment levels under four experimental conditions; however, these reflect the lower end of the observed overall engraftment rate in the experiment. Figure 1 of this Amendment shows the corrected panels for Extended Data Fig. 6e, with images from the original experiment that best reflect the differences in, and the overall level of, the engraftment rates between the conditions under study (the original images from Extended Data Fig. 6e are shown for comparison).

Changes are highlighted in red. The data point that changes is also marked in red in the original figure as well as in the corrected figure.

In addition, in Extended Data Fig. 7m, n, p, r, 9i, q–s and 10d, e of the original Letter, errors occurred in data scaling that affect the calculation of P values and the graphical presentation of the data. See Figs. 5, 6 and 7 of this Amendment for the corrected and incorrect panels for Extended Data Fig. 7f, m, n, p–t, 9i, m, q–s and 10d, e, g, respectively, and Supplementary Information to this Amendment for the corrected Source Data. The errors in data scaling occurred because two methods of data scaling were used throughout the study. In some experiments, data of the experimental groups were scaled to the average of the control values; in other experiments, data of the experimental groups were scaled to each of the corresponding controls of a biological repeat, set to 1 or 100. Although both methods of scaling are valid, they should not be combined within one experiment, which happened in the aforementioned figures. This has now been corrected and we include a detailed description of our scaling approach in the Supplementary Information to this Amendment.

Fig. 5: This is the corrected Extended Data Fig. 7f, m, n, p, r–t (right) and the original Extended Data Fig. 7f, m, n, p, r–t (left) published in. the original Letter. Changes are highlighted in red. Full size image

Fig. 6: This is the corrected Extended Data Fig. 9i, m, q, r, s (right) and the original Extended Data Fig. 9i, m, q, r, s (left) published in the original Letter. Changes are highlighted in red. Full size image