IQSEC1 and breast cancer: We have shown that an Arf6 pathway, in which Arf6 is activated by GEP100, a guanine nucleotide exchanging factor (GEF) for Arf-GTPases, and employs AMAP1 (also called DDEF1 or ASAP1) as its downstream effector, is pivotal for the invasion and metastasis of different breast cancer cells [20-25].