Correction: Tickner, Z.J.; Farzan, M. Riboswitches for Controlled Expression of Therapeutic Transgenes Delivered by Adeno-Associated Viral Vectors. Pharmaceuticals 2021, 14, 554

In the original article, Renzl, C.; Kakoti, A.; Mayer, G. Aptamer-Mediated Reversible Transactivation of Gene Expression by Light. Angew. Chem. Int. Ed. 2020, 59, 22414, doi:10.1002/anie.202009240 was not cited [1]. The citation has now been inserted in Section 2.8: Regulation of CRISPR-Cas Activity by Riboswitches, paragraph 2, and should read: A particularly interesting case was recently reported by Renzl et al., who incorporated aptamers to the photoreceptor PAL into gRNAs and demonstrated 546-fold regulation of mRNA levels in response to light in HeLa cells [190].