A random sample of SCC tumors from our TMAs were selected to calculate tumor staging using our linear regression model when considering only p39 score.

The tables show the score for phospho-Rb S249, p39, E-cadherin and the patient´s tumor stage (first fourth columns, respectively). The fifth column shows the stage predicted by our linear regression analysis only when considering the p39 score only. The Error (sixth) columns in all five tables show the difference between the vendor score and our linear regression analysis score, a value of 0 indicating identical scores, while a number other than 0 means that the two scores were different by a magnitude equal to the number indicated in the column. p39 alone was only able to accurately predict tumor stage in 2 out of 7 samples.