ESR1 and breast carcinoma: Second, when we adjust the prognosis predictive power of CENPI expression, as calculated in Table 1, to a well-established proliferation gene expression signature [30], it remains strongly associated with poor prognosis for ER+ breast cancer but not for ER- breast cancer (p=0.0183 for all breast cancers, p=0.0067 for ER+ and p=0.5335 for ER- tumors).