Table 1. Application scheme.

	retinoic acid (RA)	BMP-4	inhibitor / agonists / antagonists
1	5 μM RA	-	-
2	-	40 ng/ml BMP-4	-
3	5 μM RA	40 ng/ml BMP-4	-
4	5 μM RA	-	38 μM Boc-D-fmk a
6	5 μM RA	40 ng/ml BMP-4	38 μM Boc-D-fmk
7	-	-	5 μM TTNPB b
8	-	40 ng/ml BMP-4	5 μM TTNPB
10	-	-	5 μM methoprene acid c
11	-	40 ng/ml BMP-4	5 μM methoprene acid
13	5 μM RA	-	10 μM ER50891 d
15	5 μM RA	40 ng/ml BMP-4	10 μM ER50891
16	5 μM RA	-	10 μM LE135 e
18	5 μM RA	40 ng/ml BMP-4	10 μM LE135

^aBOC-D-fmk: caspase inhibitor

^bTTNPB: RAR agonist

^cmethoprene acid: RXR agonist

^dER50891: RARα antagonist

^eLE135: RARß antagonist.