HOTAIR and Parkinson disease: Sun et al. (2022) found a HOTAIR/miR-221-3p/α-synuclein signaling axis in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-hydrochloride (MPTP)-induced mouse model of PD. Further, miR-221-3p can directly bind to HOTAIR and α-synuclein. As a ceRNA, HOTAIR regulates α-synuclein expression by sponging miR-221-3p (Sun et al., 2022).