Indicating that cells retaining 14-3-3s expression may be selected during disease progression and treatment. Indeed, an increased level of 14-3-3s expression was found in drug -selected breast cancer cell lines and androgen-independent prostate cancer cell lines more resistant to mitoxantrone and adriamycin compared to androgen-dependent cell lines. In accordance with these findings, one paclitaxel-resistant sub-line EC9706/PTX and one cisplatin-resistant sub-line EC9706/CDDP derived from the same parental cell line EC9706 showed higher levels of 14-33s protein expression compared with immortalized NEC and ESCC cell lines. Furthermore, a high level of 14-3-3s in patients at the advanced clinical stage and with lymph node metastasis did not predict good clinical outcome contrasting sharply with its role in ESCC patients at early clinical stage and negative lymph node metastasis. Taken together, we propose that recovery from 14-3-3s suppression could enhance progression of later stage ESCC and contribute to paclitaxel/cisplatin-resistance during therapeutic intervention. In cancers with lymph node metastases, elevated expression of 14-3-3s was frequently observed in ovarian cancer, gastric cancer, endometrial cancer, pancreatic cancer and nasopharyngeal carcinoma. A study from Japan reported that elevated nuclear expression of 143-3s in 248 ESCC patients was significantly correlated with depth of invasion, clinical stage and lymphatic invasion whereas there was no association between cytoplasmic expression of 14-3-3s and clinical factors. In sharp contrast, predominant cytoplasmic staining of 14-3-3s was observed, and notably, decreased or complete loss of 14-3-3s expression was significantly correlated with lymph node metastasis in another study using ESCC samples from China. In our study, 14-3-3s protein was mainly located in the cytoplasmic and plasma membrane and less frequently in the nuclei, in particular in late stage ESCC. In addition, the decreased expression of 14-3-3s that correlated with histological grade by IHC analysis was inconsistent with Western blot results of a correlation with clinical stage. The precise reason for these discrepancies is unknown but possible explanations include geographical location, hereditary factors, environmental factors, technical issues in sample processing, disease stage, etc. In the current study, the samples used for Western blot were fresh frozen from Linzhou Cancer Hospital, Henan whereas the samples for IHC analysis were formalin-fixed tissue from Huaihe Hospital, Henan and TMA from Shanghai and this may affect the 14-3-3s expression pattern. Clearly more studies are needed to elucidate the functions of 14-33s in the progression of specific cancers. Current clinical staging systems for ESCC are of limited value in prognosis and novel molecular biomarkers with prognostic value are urgently required.