– CBL proteins, such as Cbl-c, are phosphorylated upon activation of a variety of receptors that signal via protein tyrosine kinases. Through interactions with proteins containing SRC homology-2 (SH2) and SH3 domains, CBL proteins modulate downstream cell signaling. Cbl-c is a member of the Cbl family of E3 ubiquitin ligases. Expression of Cbl-c gene may be restricted to epithelial cells, and alternatively spliced transcript variants encoding multiple isoforms have been observed for Cbl-c gene.