Aim 1:  Examine if common genetic variants of EGF-R ERBB2, CSF-1R and IGF-1R are associated with increased risk of breast cancer.

Aim 2:  Examne if rare variants of EGF-R, ERBB2, CSF-1R and IGF-1R display distinct functional activities and if so, whether they are associated with familial breast cancer.

Aim 3:  Protein expression status in tissue microarrays of breast cancer tumors.

Aim 4:  Plasma levels of protein ligands are associated with subsequent breast cancer risk.