In Cos-7, HeLa or N1E-115 and Neuro2a neuroblastoma cell lines, overexpressed PLPPR1, PLPPR3, PLPPR4 and PLPPR5 were located at variable levels to the plasma membrane (Bräuer et al., 2003; Savaskan et al., 2004; Sigal et al., 2007; van Coevorden-Hameete et al., 2015; Brosig et al., 2019; Tilve et al., 2020), while PLPPR2 overexpressed in HEK293 was observed mostly in intracellular compartments (Gross et al., 2021; Figure 2C). The gene discussed is PLPPR4; the disease is neuroblastoma.