PTEN and retinoblastoma: In FAB4 relatively high PTEN level was detectable in the majority of PTEN-positive patients (N = 11/9, Pearson Chi-Square test p = 0.048) In FAB5 relatively high PHLPP expression was found in every PHLPP positive patients (N = 3/3 Pearson Chi-Square test p = 0.006) Among FAB6 patients relatively low phospho-Retinoblastoma level was found and only one patient had relatively high phospho-Retinoblastoma level (N = 4/1 Pearson Chi-Square test p = 0.026) There was no significant correlation between the expression level of the other proteins and FAB groups.