SMAD3 and neoplasm: To identify nuclear actin binding partners that function in transcriptional regulation, we found that nuclear F‐actin bound EMT‐promoting transcription factors β‐catenin, SMAD2 and SMAD3, and nuclear G‐actin bound tumor‐suppressing transcription factors MYB Binding Protein 1a (MYBBP1A), NF‐kappa‐B‐repressing factor (NKRF), and MYB‐related transcription factor (MYPOP), resulting in EMT repression.