RARs/RXR
RAR (The retinoic acid receptor) is a type of nuclear receptor which can also act as a transcription factor that is activated by both all-trans retinoic acid and 9-cis retinoic acid. There are three retinoic acid receptors (RAR), RAR-alpha, RAR-beta, and RAR-gamma. Each receptor isoform has several splice variants: four- for alpha, four- for beta, and two- for gamma. RXR (The retinoid X receptor) is a type of nuclear receptor that is activated by 9-cis retinoic acid. There are three retinoic X receptors (RXR): RXR-alpha, RXR-beta, and RXR-gamma. RXR heterodimerizes with subfamily 1 nuclear receptors including CAR, FXR, LXR, PPAR, PXR, RAR, TR, and VDR.