The cells, following coculture experiments, were fixed in 2% paraformaldehyde and blocked with 3% BSA. Primary antibodies used were: rabbit anti-citH3 (1:150, Abcam) and mouse anti-NE (1:150, Hycult Biotech), or the respective isotype controls, followed by incubation with goat anti-mouse IgG AF555 (1:1,000, A21424) and goat anti-rabbit IgG AF488 (1:1,000, A11034, Invitrogen Life Technologies). DNA was counterstained with DAPI (1:10,000).