ASB2α is an E3 ubiquitin ligase which is upregulated during Th2 differentiation of naive CD4+ T lymphocyte, and which is known to trigger ubiquitylation and proteasomal degradation of filamins (FLN) a and b. Because E3 ubiquitin ligases often ubiquitylate several substrates, we used an unbiased and broad mass spectrometry approach to identify ASB2α substrates in Th2 lymphocytes generated from naïve CD4+ T lymphocytes of control or ASB2 KO mice.