['The objective of this study was to establish the identity of a protein found in high concentrations in squamous metaplasia of the bladder.', 'The protein was isolated and subjected to a series of physical, chemical, and catalytic studies.', 'In the normal urothelium the protein was confined to a juxtanuclear pattern on the luminal side of the umbrella cells; in squamous metaplasia and squamous cell carcinoma the protein was increased and exhibited a more diffuse intracellular distribution. The protein was found to be identical to triosephosphate isomerase (EC 5.3.1.1; TPI) with respect to its immunological properties, native and subunit molecular weights, electrophoretic mobility, catalytic activity, and amino acid sequence.'] Is the 28K protein in urinary bladder , squamous metaplasia and urine triosephosphate isomerase?