To investigate the specificity of protein degradation and identify potential neo-substrates for the OsTIR1-AID2 and hCRBN-S4D systems, we conducted proteomics analyses of thymocytes 16 hours after intraperitoneal injection of 5-Ph-IAA or PBS in Rosa26OsTIR1/+;Satb1V-AID/V-AID and Rosa26OsTIR1/+;Satb1 +/+ mice, as well as POM or DMSO in Rosa26hCRBN/+;Satb1V-S4D/V-S4D and Rosa26hCRBN/+;Satb1+/+ mice, alongside with wildtype control mice. Furthermore, we conducted proteomics analysis in the cerebrum of DMSO- and POM-treated Rosa26hCRBN/+;Satb1+/+ mice to identify neo-substrates in the brain for the hCRBN-S4D system.