This pathway catalogues RAC3 guanine nucleotide exchange factors (GEFs), GTPase activator proteins (GAPs), GDP dissociation inhibitors (GDIs) and RAC3 effectors. RAC3 is highly similar to RAC1 (92% amino acid sequence identity), but it is expressed in fewer tissues than RAC1. RAC3 orthologues only exist in vertebrates (de Curtis 2019). RAC3 is highly expressed in neurons and plays an important role in neuronal and brain development (de Curtis 2014, de Curtis 2019). RAC3 mutations have been reported in patients with intellectual disability and brain malformations (de Curtis 2019). RAC3 is frequently overexpressed in cancer and contributes to proliferation, migration and invasiveness of cancer cells (de Curtis 2019).