Tab. 1: Overview of retinoid pathway targets reviewed.

Table identifiers with “S” are supplemental¹.

Section	Retinoid target	Long name	Basic function	Data source and entries	Table
3.1	RBP	Retinol binding protein (serum / plasma)	Transports dietary derived and in situ synthesized retinol in serum	PDB entries	S1
				ChEMBL assays	S2
3.2	STRA6	stimulated by retinoic acid gene 6 protein	Transports retinol across membrane into cell from bloodstream; receptor for retinol uptake; signaling	PDB entries	S3
3.3	CRBP (CRBP1, CRBP2, CRBP3)	Cellular retinol binding protein	Binds retinol inside the cell	PDB entries	S4
3.4	CRABP (CRABP1, CRABP2)	Cellular retinoic acid binding protein	Binds ATRA; facilitates transfer of ATRA from cytosol to nucleus	PDB entries	S5
				ChEMBL assays	S6
				Fogh et al., 1993	2
				Chaudhuri et al., 1999	2
3.5	CYP26	Retinoic acid 4- hydroxylase OR cytochrome P450 family 26	Degradation of ATRA	ChEMBL assays	S7
				Thatcher et al., 2011; Buttrick, 2013; Foti et al., 2016a,b	3
3.6	RDH	Retinol dehydrogenase	Transforms retinol to retinal through dehydrogenation	ChEMBL assays	S8
3.7	ALDH / RALDH	Aldehyde dehydrogenase / retinal dehydrogenase	Transforms retinal to ATRA through dehydrogenation	PDB entries	S9
				ChEMBL assays	S10
				Koppaka et al., 2012	6
3.8	RARa	Retinoic acid receptor alpha	ATRA receptor	PDB entries	S11
				ChEMBL assays	S12
				ToxCast assay results	S17
3.9	RARb	Retinoic acid receptor beta	ATRA receptor	PDB entries	S13
				ChEMBL assays	S14
				ToxCast assay results	S17
3.10	RARg	Retinoic acid receptor gamma	ATRA receptor	PDB entries	S15
				ChEMBL assays	S16
				ToxCast assay results	S17
3.11	Retinoid pathway	Retinoid pathway		Chen and Reese, 2013; Chen et al., 2016b	7
				ToxCast / Tox21 assay results	S17