This project aims to investigate how different PEAK3 mutations affect phosphorylation at serine 69 (S69). To this end, we performed proteomic analyses on immunoprecipitated (IP) PEAK3 samples from both wild-type and mutant constructs. Peptides containing phosphorylated and non-phosphorylated S69 were specifically identified and compared to assess mutation-dependent changes in S69 phosphorylation.