Vorselen et al. (2018) have also found evidence of MAS proteins in EVs both from normal donors and patients with hereditary spherocytosis. It should be kept in mind that EVs can arise from a variety of mechanisms, and that these will likely lead to significant heterogeneity in composition and properties. It is also the case that methods used to isolate and identify EVs will likely lead to the preparation of different populations of EV’s reflecting contributions from different types of EVs and different levels of contamination (Hebbel and Key, 2016; Lapping-Carr et al., 2020). The gene discussed is MAS1; the disease is hereditary spherocytosis.