Detection and initiation of the most appropriate therapy at an early stage of breast cancer are two major determinants of a successful anticancer therapy. In this context, it is important to continue to identify novel biologic endpoints (commonly known as biomarkers) which also facilitate therapeutic decisions. Here we briefly review the following pathways from the perspective of biomarkers through works from Dr Kumar's lab: i) estrogen receptor alpha (ER) signaling; ii) nuclear receptor coregulators in ER-directed therapies; iii) p21-activated kinase-1 in ER action; iv) cytoskeleton components in breast cancer cell progression; v) emerging molecules as biomarkers. We believe that the potential usefulness of the cytoplasmic kinases, coregulators, and cytoskeleton molecules is likely to accelerate the development of the next generation of biomarkers for the surveillance, prognosis and therapeutic decisions for cancer.