[The prognostic significance of the PCNA protein in transitional-cell bladder cancer]

1. Apparent expression of PCNA in different tumours should not be regarded as an unquestionable criterion of tumoral growth and progression but a negative result of an immunohistochemical assay for PCNA of certain human tumours is not to be taken as a proof that there is no tumoral growth whatever. 2. With results of the immunohistochemical study into the tumour for PCNA protein varying thus much, they are to be interpreted as different forms of manifestation of this protein gene abnormalities.