['Numerous studies have proven that protein tyrosine phosphatase type IV A member 3 (PTP4A3) plays a significant role in local lymph node metastasis from colorectal carcinoma. The aim of the current study was to assess PTP4A3 expression in colorectal carcinomas and lymph nodes in correlation with chosen anatomoclinical parameters.', 'Forty-nine patients were analyzed with respect to age, tumor location, pTN stage and local lymph node involvement. The level of PTP4A3 expression was determined immunohistochemically using mouse monoclonal anti- PTP4A3 antibody (monoclonal antibody 3B6, anti-human PTP4A3 from Attogen Biomedical Research, USA).', 'Positive reaction for PTP4A3 in the main tumor mass was observed in 9/49 (18.4%) cases, whereas in metastatic lymph nodes in 22/24 (91.6%) cases. Statistical analysis showed no correlation of PTP4A3 expression in the main tumor mass with such clinical parameters as age, location, histological type or lymph node involvement. Moreover the expression of PTP4A3 in the main tumor mass was not associated with the expression of this protein in lymph node metastases. However, there was a statistically significant correlation between lymph node involvement and PTP4A3 expression in lymph node metastases.'] Does pTP4A3 expression increase strongly in lymph node metastases from colorectal carcinoma?