To rule out the possibility that TNF-α was induced by a mycoplasma other than M. hyorhinis, mycoplasma-free PCa cells (PC3–P and C4–2B–P cells) were treated with M. hyorhinis for 7 weeks (PC3-M and C4–2B-M cells, Fig. 1B). Here, TNF is linked to posterior cortical atrophy.