CS1 expression is correlated with OSCC in tissues and cells. (A) Schematic representation of the domain structure of human fibronectin and the possible protein products arising from alternative splicing of the IIICS region. (B) CS1 expression levels in normal and SCC tissues are illustrated. CS1 staining intensity low and high are shown in low (a, e, b and f) and high magnification (c, g, d and h) images (Arrows, epithelium, arrowheads, connective tissue). (C) Immunoblot showing CS1 levels in normal kerotinocytes (K1, K2, two different patient isolates) and SCC cells (HSC-3, UM-SCC1, UM-SCC17B, UM-SCC14A and OSCC3) and fold change shows results from densitometric analysis of CS1 normalized to β-actin. Plasma fibronectin (plasma FN) served as positive control. (D) CS1 and fibronectin expression levels in normal and SCC tissues are illustrated (Arrows, epithelium; arrowheads, connective tissue). (E) Immunoblots showing the levels of CS1 and fibronectin in kerotinocytes and SCC cells.