Through a comment in Pubpeer, it was brought to our attention that in the western blots shown in Fig. 1b, the bands for IKK2 in spleen were similar to the bands for IKK1 in MEFs. By checking our original raw data files, we could confirm that the bands for IKK2 in spleen extracts were correct, but these were inadvertently duplicated and appeared also as bands for IKK1 in MEFs due to a figure preparation error. Due to the age of the article, the figure cannot be replaced directly. The Supplementary information accompanying this amendment serves to update the article.