SLC6A4 and transient ischemic attack: In patients undergoing the hyperacute phase (<4.5 h) of brain ischemia, platelet 5-HT2AR density was higher than in controls, while the platelet density of SERT was significantly lower, which coincides with the analysis of genetic polymorphisms in 834 patients with AIS and TIA, revealing that the presence of the high-expression SERT genotype is linked to a lower risk of ischemic stroke [201].