GREM1 and neoplasm: Fregni et al. revealed that the reconstitution of normal adjacent lung tissue-derived mesenchymal stem cells with four genes, GREM1, LOXL2, ADAMTS12, and ITGA11, contributed to the increased ability of tumor-associated mesenchymal stem cells to induce primary tumor cell dissemination (Fregni et al. 2018), indicating its possible linkage to PMN formation.