PHB1 and neoplasm: Furthermore, subcellular location assay may provide clues regarding the possible molecular mechanism of PHBP1 exerting its biological function in cytoplasm as PHBP1 was predominantly located in cytoplasm of ESCC cell lines, similar to PHB. Both in vitro and in vivo data showed that the silence of PHBP1 induced cell cycle arrest at the G0–G1 phase and significantly inhibited proliferation and tumor growth of ESCC cells.