HMGA2 and smooth muscle tumor: Consistent with published immunohistochemical analysis and RNA studies [9,12,14,37,38,39,40], expression of the chromatin factor HMGA2, a protein which is highly expressed in a subset of both IVLM and uterine leiomyomas due to the breakpoint on 12q14–15 [11,12,14], was not significantly different between IVLM and the other smooth muscle tumours in the cohort (Figure S1).