Which data format for mRNA expression matrix is necessary to run pathway analysis with Paradigm?

Question

[fbrundu]

I am running Paradigm on a matrix of mRNA expression. I read

Vaske, Charles J., et al. "Inference of patient-specific pathway activities from multi-dimensional cancer genomics data using PARADIGM." Bioinformatics 26.12 (2010): i237-i245.

and also the help section in the web application. However it is not defined which format is best-suited for mRNA expression. Using log2-ratios instead of log2 data format gave me different results.

Thanks