RAC2 and immunodeficiency disease: Patients with Rac2 dysfunction secondary to dominant negative or homozygous LoF mutations present early-onset recurrent abscesses, neutrophilia, and defective wound healing, whereas monoallelic germline GoF mutations of the same RAC2 gene cause a severe combined immunodeficiency (no. 13 in Table 1 and Figure 1) (74–77).