Similar to human urothelial carcinoma, the S100A8/A9 gene has been shown to harbour an increased frequency of copy number gains in canine urothelial carcinoma [33], and pilot data by our group suggested that the urinary concentration of S100/calgranulins, particularly the S100A8/A9-to-S100A12 ratio (uCalR), may have potential as a diagnostic biomarker for TCC/PCA in dogs [34]. Here, IGKV1D-22 is linked to tarsal-carpal coalition syndrome.