CCND1 and breast cancer: hSulf-1 is also involved in the inhibition of autocrine-mediated phosphorylation of EGFR-ERK in breast cancer cells induced by serum starvation, and the inhibition of autocrine EGFR-ERK signaling by hSulf-1 results in a reduced expression of Cyclin D1, a decreased S phase fraction and an increased G2-M fraction, and finally leading to the inhibition of cell survival in breast cancer cells [7].