HUVECs do not respond to canonical SHH signaling. (A) Immunofluorescence of HUVECs stained for acetylated tubulin (AcTUB; cyan), ARL13B (magenta), and nuclear DAPI (blue). Magenta arrowhead denotes an ARL13B-positive cilium. From 419 cells counted, 0.95% were positive for ARL13B. Scale bar, 10 µm. n = 3 replicates. (B) Quantitative RT-PCR for GLI1, PTCH1, and GLI2 expression in HUVECs treated with SAG (200 nM) for 24 h, using 18S rRNA as an internal control. Data are presented as mean ± SD, n = 9 replicates, pooled from three experiments.