There was an error in J. Cell Sci. (2021) 134, jcs248393 (doi:10.1242/jcs.248393).

In the section on disease-associated mutations and rare Trio variants, the authors stated that the Trio K1431M mutation found in ASD increases GEF1 activity by eight-fold, when this should have referred to a decrease.

The original sentence was: For instance, the Trio K1431M mutation found in ASD increases GEF1 activity by eight-fold (Katrancha et al., 2017; Sadybekov et al., 2017) and disrupts the ability of Trio to support normal synapse development (Sadybekov et al., 2017).

The correct sentence should read: For instance, the Trio K1431M mutation found in ASD decreases GEF1 activity by eight-fold (Katrancha et al., 2017; Sadybekov et al., 2017) and disrupts the ability of Trio to support normal synapse development (Sadybekov et al., 2017).

The text has been updated in the PDF and online versions.

The authors apologise to readers for this error.