(A) HVEM and LTβR expression on human ASM assessed by flow after stimulation with LIGHT for 24 or 48hr. Similar data in 3 experiments. (B) Images of ASM in collagen 3D gels. Left: Bright field, Right: Phalloidin (red), DAPI (blue). (C) ASM collagen gel contraction at 24–72hr after stimulation with LIGHT. Data combined means from triplicates from 3 experiments. (D) Percentages of BrdU+ ASM stimulated with LIGHT for 48hr. Cells either first incubated in serum free media for 16 hours for proliferative ASM, or for 7 days for contractile ASM. Data means of triplicates and representative of 3 experiments. (E) ASM volume after stimulation with LIGHT, measured by confocal microscopy. 300–400 ASM, in two replicate experiments were analyzed. Data means ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.