Accelerated receptor recycling and increased excretion/secretion of matrix components, adhesion molecules and growth factors usually accompany the rapid proliferation of cancer cells (Hu and Polyak, 2008), which was reflected in our observation that intracellular and membrane-associated proteins were identified with high abundance in cell growth environment, such as MRPL15, PPARD, MAP4 and OR5A2. Here, PPARD is linked to cancer.