STX4 and neoplasm: Some, likethe DEP1 phosphatase, has already been associated with tumour-suppressormechanisms.48 Others, such as STX4,VAMP3, VPS26A and PLD3, may all have a role in vesicle trafficking in thecell,49, 50,51, 52, 53, 54 perhapscontributing this way to some aspects of the SASP.