Disclosed are isolated antibodies that specifically bind a murine pituitary tumor transforming gene carboxy-terminal (PTTG-C) peptide. The inventive antibodies are useful in assays to determine levels of PTTG proteins or PTTG-C peptides present in a given sample (e.g., tissue samples, biological fluids, Western blots). The antibodies can also be used to purify PTTG proteins or PTTG-C peptides from crude cell extracts and the like. The antibodies are also considered therapeutically useful to counteract and/or supplement the biological effect of PTTG proteins in vivo.