Updated project metadata. SMYD3, a member of the SET and MYND domain-containing (SMYD) family, is a histone methyltransferase (HMT) and transcription factor that plays an important role in transcriptional regulation in human carcinogenesis.In an effort to better understanding the mechanistic role of SMYD3, affinity purification and mass spectrometry assays were used to identify proteins associated with SMYD3 in vivo. In these experiments, FLAG-tagged SMYD3 or an empty vector was stably expressed in LM3 cells. Cellular extracts were prepared and subjected to affinity purification using an anti-FLAG affinity gel. Immunocomplexed proteins were separated using SDS–PAGE and silver stained. Immunoprecipitated proteins in specific bands in comparison to the vector were gel extracted, trypsin digested and identified using liquid chromatography tandem mass spectrometry.