Collectively, our current findings – i.e. the identification of RasGRP3 as an additional important signaling element together with the evidence for its elevated expression in a subpopulation of breast tumors – identify RasGRP3 as a novel, promising target molecule for pathway directed chemotherapy in the supportive treatment and diagnosis of ductal adenocarcinoma of human breast. This evidence concerns the gene RASGRP3 and invasive ductal breast carcinoma.