The 5-HT1A agonists so far evaluated in clinical trials have shown off-target effects and only partial agonist efficacy at 5-HT1AR. In this contest, the new highly selective 5-HT1AR biased agonists F13714, F15599, and Befiradol (also known as F13640 or NLX112) were recently demonstrated to exhibit exceptionally potent antidyskinetic activity in animal models of PD, while minimally interfering with LD antiparkinsonian effects [99,100,101]. Here, HTR1A is linked to Parkinson disease.