SIPS expressed cytoskeletal proteins and extracellular matrix proteins. Cells were grown directly on slides. Immunostaining for α-SMA (A), glial fibrillary acidic protein (B), vimentin (C), desmin (D), type I collagen (E), fibronectin (F), and prolyl hydroxy-lases (α) (G) and (β) (H) was performed using a streptavidin-biotin-peroxidase complex detection kit. Original magnification: ×20 objective.