GREB1 activation in humans with lung metastasis.

Hormone receptor control during the progression of breast cancer in humans differs based on disease stage and site of metastasis. We recently described induction of GREB1 during resistance to endocrine therapy in humans with hormone receptor-positive breast cancer, a co-receptor-type nuclear factor activated during development of the breast in humans and during transformation of the breast, a molecule whose identity we discovered in genome-wide expression screens to discover novel factors associated with resistance to clinical interventions. We report here discovery of GREB1 activation during metastasis to the lung in humans with breast cancer. The tumor thus undergoes another wave of GREB1 activation prior to or during metastasis to the lungs.