MDS analysis of the ten FF bladder carcinoma samples and the three FF/FFPE pairs of Ta tumours based on the expression profiles of the genes included in the 12-gene expression signature for bladder carcinoma progression (BIRC5, CDC25B, COL18A1, COL4A1, COL4A3BP, FABP4, KPNA2, MBNL2, MSN, NEK1, SKAP2 and UBE2C) [27], resulted in separation of the recurrent bladder carcinoma samples from the progressing bladder carcinoma samples in dimension 1 (horizontal) and a separation of the progressing bladder carcinoma samples in dimension 2 (vertical) (Figure 7A). Here, COL4A1 is linked to urinary bladder carcinoma.