To explore kinome activation in this population, we propose a window trial in stage I-IV HER2+ patients scheduled to undergo definitive surgery (either lumpectomy, mastectomy or surgical resection of oligometastatic disease). Enrolled patients will be randomized to one of four treatment arms; A) single dose trastuzumab; B) single dose pertuzumab; C) combination trastuzumab + pertuzumab for one dose each; or D) combination single dose trastuzumab plus lapatinib daily for one week.