Pretherapy ovarian cancer ribonucleotide reductase (RNR) M1, M2, and M2b (p53R2) protein is associated with 3-aminopyridine-2-carboxyaldehyde-thiosemicarbazone (3-AP) then cisplatin treatment response. Panel A: Two pathologists blinded to treatment and outcome scored intensity of ribonucleotide reductase subunit staining. Corresponding best treatment responses are listed (S = stable, PD = progressive disease, PR = partial response, U = undetermined). Panel B: Progression-free survival (PFS) and overall survival are illustrated for six treated patients by 3-AP (96 mg/m2) given days 1 through 4 and cisplatin (25 mg/m2) given on days 2 and 3 every 21 days. A median 14-week PFS and median 28-week overall survival were observed.