SOX4 and urinary bladder cancer: However, the identity of the gene on chromosome 1q23.3 was not well-defined from previous work, and for chromosome 6p22.3, there were two candidate genes, E2F3 and SOX4. Hence we chose to analyze 16 distinct genes (Table 4) in a replication study to validate the MIP findings, and examine the possible association of amplification of these regions with bladder cancer stage and grade.