The function of UBASH3A (ubiquitin associated and SH3 domain containing A, ENSG00000160185) is as follows. Interferes with CBL-mediated down-regulation and degradation of receptor-type tyrosine kinases. Promotes accumulation of activated target receptors, such as T-cell receptors, EGFR and PDGFRB, on the cell surface. Exhibits negligible protein tyrosine phosphatase activity at neutral pH. May act as a dominant-negative regulator of UBASH3B- dependent dephosphorylation. May inhibit dynamin-dependent endocytic pathways by functionally sequestering dynamin via its SH3 domain. {ECO:0000269|PubMed:15159412, ECO:0000269|PubMed:17382318, ECO:0000269|PubMed:18189269}.