Although persistent epigenetic changes that potentially regulate mechanical memory have not yet been identified in tumor cells but have been found in mesenchymal stem cells,133,134 a recent study has shown that increased matrix stiffness can increase lamina-associated chromatin and there are more accessible chromatin sites binding to Sp1 transcription factor in cells embedded in 2 kPa 3D hydrogels than those in 0.1 kPa hydrogels,135 suggesting that phenotypic adaptations of tumor cell maybe retained via mechanical memory encoded by persistent epigenetic changes. The gene discussed is SP1; the disease is neoplasm.