In the article “On the Structure of Cortical Microcircuits Inferred from Small Sample Sizes” by Marina Vegué, Rodrigo Perin, and Alex Roxin, which appeared on pages 8498–8510 of the August 30, 2017 issue, an incorrect affiliation for author Alex Roxin was listed. The authors apologize for the oversight. His corrected affiliation is as follows: 2Centre de Recerca Matemàtica, Campus de Bellaterra, Edifici C, 08193 Bellaterra, Spain. This correction does not affect the conclusions of the paper. The author line has been corrected on the online PDF version.