Kim et al. demonstrated that exosomes isolated from iPSC-derived mesenchymal stem cells (iMSCs) enhance tumor growth and cell proliferation in a human keratinocyte tumor cell line (HaCaT) via phosphorylation of extracellular signal-regulated kinase (ERK)-1/2, indicating potential clinical importance of iMSC-derived exosomes [84]. Here, MAPK3 is linked to neoplasm.