MFB‐F11 cells were cultured as described previously (Tesseur et al, 2006 (link)). In brief, 20 000 MFB‐F11 cells were seeded per well in 96‐well plate until 70% confluency. Cells were washed twice with 1× PBS, followed by incubation with medium from the co‐culture experiments for 24 h at 37°C, 5% CO2. SEAP assay was carried out using Great EscAPe SEAP Chemiluminescence kit (Takara, 631738) according to the manufacturer’s instruction.