“13C Natural Isotope Abundance in Urothelium as a New Marker in the Follow-up of Patients with Bladder Cancer” Adam Madej, Ewa Forma, Michał Golberg, Rafał Kamiński, Piotr Paneth, Józef Kobos, Waldemar Różański, Marek Lipiński Cancers 14, 2423 (2022)