A cell of a layer of transitional epithelium in the wall of the proximal urethra, bladder, ureter or renal pelvis, external to the lamina propria. [ GOC:tfm http://www.informatics.jax.org/searches/AMA.cgi?id=MA:ma doi:10.1038/s41385-022-00565-0 ]
This is just here as a test because I lose it