CD81 and prostate cancer: Manipulation of the AR signalling axis alters the protein cargo in S‐EVs in LNCaP prostate cancer cells, and that the tetraspanin CD9 has been shown to be significantly more abundant in EVs from DHT‐treated cells when comparison with other S‐EVs markers including: TSG101, Alix, CD63 and CD81 (Soekmadji et al., 2016; Soekmadji et al., 2017; Soekmadji et al., 2017).