Status of several members of the RB and p53 pathways in cells treated with β-interferon. (A) Immunoblots for RB and various members of the RB pathway. (B) Immunoblots for p53, its modifications, and targets. C+, positive control. (C) RT-PCR for PIG-3, p21, and β-actin in cells treated for 6 or 12 d with β-interferon, or cells treated with adryamicin (Ad).