Immunohistochemically, neoplastic cells of angiomyxoma often display variable positivity for α-SMA and desmin (Gajanayake et al. 2010; Lee et al. 2016a; Okada et al. 2005; Shaver, Kolker & Bennett 2018), and a myofibroblastic phenotype has been hypothesised (Gajanayake et al. 2010). Here, ACTA1 is linked to angiomyxoma.