MMP9 and urinary bladder cancer: The uremic toxin p-C appears to have a pro-oncogenic role in bladder cancer by promoting the invasion and the migration of urothelial cells by increasing the expression of the matrix metallopeptidase 9 (MMP9) and the levels of RAS proteins, Ras homolog family member A (Rho A), the mechanistic phosphorylated target of rapamycin (p-mTOR) and protein complex functioning as a transcription factor (NF-κB).