In addition, an association between a cyclin dependent kinase inhibitor 1B (Cdkn1b) variant (c.326T>G) and tumour multiplicity in MEN1 patients has been reported (41), although we did not observe any variants in Cdkn1b (encoding p27kip1) in our WGS data, we did observe variants in the cell cycle regulator, Ccne2, that is regulated by p27kip1. Here, CDKN1B is linked to neoplasm.