Similarly, exposure to silibinin resulted in a dose- and time-dependent growth inhibition, together with G1 arrest in bladder transitional cell carcinoma cells, which was also associated with upregulation of Cip1/p21 and Kip1/p27 and inhibition of CDKs and cyclins involved in G1 progression [38]. The gene discussed is PCNA; the disease is bladder transitional cell carcinoma.