Negatively regulates Ras signaling pathways and downstream activation of MAP kinases (PubMed:11493923). Inhibits fibroblast growth factor (FGF)-induced retinal lens fiber differentiation, probably by inhibiting FGF-mediated phosphorylation of ERK1/2 (PubMed:29501879). Inhibits TGFB-induced epithelial-to-mesenchymal transition in lens epithelial cells (PubMed:25576668). Homodimer and heterodimer (By similarity). Able to interact with SPRED1 to form heterodimers (By similarity). Interacts with RAS (PubMed:11493923). May interact with ZDHHC13 (via ANK repeats) and ZDHHC17 (via ANK repeats) (PubMed:28882895). Interacts with TESK1 (PubMed:17974561). Detected in the cytoplasm of the stratum spinosum cells, where it is associated with cytoplasmic vesicles that are supposed to be secretory granules. Predominantly expressed in lung, liver and testis. In testis, it is specially found in mature spermatids projecting into the lumen of the seminiferous. Strongly expressed in glandular epithelia. Also expressed in embryonic tissues such as heart, lung, liver and brain. Phosphorylated on serine and threonine residues. Phosphorylated on tyrosine. Phosphorylation of Tyr-224 and Tyr-227 are required for ubiquitination. Ubiquitinated; leading to degradation by the proteasome.