Spp1 is known to induce TGFβ1-dependent myofibroblast activation through increased Smad2/3 phosphorylation34, and its expression in UTI females was largely restricted to mPCs, while males exhibited diffuse expression of Spp1 throughout the CD, consistent with their phenotypic susceptibility to post-pyelonephritic scarring7,9. Here, TGFB1 is linked to bacterial urinary tract infection.