GREM1 and cancer: The pathogenesis behind HMPS stems from a large duplication just upstream of the Grem1 gene, resulting in Grem1 overexpression, and the development of polyps of mixed morphologies from a young age.81 At elevated levels, Grem1 has been linked to tumour progression and risk of metastatic dissemination in several types of cancers.79,82 Therapeutic targeting of Grem1 may prove to be a pivotal therapeutic avenue that can alter the fate of cancer driven by the BMP pathway, though future studies are needed to elucidate this.83