Fg (immunoreactive Fgα, Fgβ, and Fgγ chains) protein is expressed in the kidney of rats and humans. (A) Representative formalin-fixed paraffin-embedded kidney tissue sections of sham male Wistar rats and those from rats that had undergone 20 minutes of bilateral ischemia reperfusion stained for immunoreactive proteins to Fgα (i-iii), Fgβ (iv-vi), Fgγ (vii-ix), and Fg (x-xii) after 24 and 72 hours of reperfusion and compared with healthy (sham) kidneys. Bar represents 50μm. (B) Representative formalin-fixed human-biopsied kidney sections of AKI and non-AKI patients, stained for immunoreactive molecules recognizing Fgα (i-ii), Fgβ (iii-iv), Fgγ (v-vi), and Fg (vii-viii). Bar represents 50 μm. Arrowheads indicate respective immunoreactive molecules. Asterisks in panels Bvii and Bix mark tubules with similar expression pattern along the basolateral side of respective tubules.