HUVEC infected with lentivirus expressing short-hairpin RNAs (see Methods) targeting CLIC1 or CLIC4 (hereafter CLIC1KD or CLIC4KD) are deficient in S1P-induced Rac1 activation and barrier enhancement when compared to controls (Mao et al., 2021), while co-infection with lentivirus expressing HA-tagged full-length CLIC1 or CLIC4 led to selective rescue of these phenotypes: HA-CLIC1 rescued phenotypes caused by CLIC1KD but not CLIC4KD, while HA-CLIC4 rescued CLIC4KD but not CLIC1KD (Mao et al., 2021). The gene discussed is RAC1; the disease is infection.