To elucidate the potential role of TKS5 in the ploidy control in urothelial cells and BC, we first determined the mRNA and protein levels in a number of ureter-derived immortal cell strains (telomerase-immortalised Y235T, SV40-immortalised UROtsa and spontaneously immortalised HBLAK) in comparison with BC cell lines with low/no (RT4) and high (UMUC3, T24 and J82) invasive capacities. This evidence concerns the gene SH3PXD2A and breast cancer.