High levels of the antibody Ki-67 was associated with higher rates of recurrence and lower survival for triple-negative patients, according to new research. And low levels signaled a less aggressive form of the disease. Researchers say this could lead to two separate subgroups of TNBC with significantly different levels of aggressiveness and prognosis. The research, on 105 patients who received neoadjuvant (after surgery) Adriamycin and Cytoxan, was published in the journal Breast Cancer Research. Antibodies are part of the immune system.