When using the --means option, shifting the data can have an effect on the results. You normally shouldn't need to shift your data, however if it contains negative intensities, then to use the --means option you must shift.
Note 1: Shifting biases against genes that are differentially expressed in the low intensity range. Note 2: Shifting has no effect when using the t-statistic.
This command takes one argument of type float.
> perl PaGE_5.1.6.pl --shift 250