I would like to know how to find the correlation between miRNA and gene expression data from TCGA. The data available in TCGA for miRNA and gene are in two different units like its RPKM for the gene and reads per million for miRNA. Thank you.
Also consider cBioPortal, which will allows retrieving sets of normalized data curated from TCGA http://www.cbioportal.org/. Also please use Pearson coefficient only if you really expect linear correlations. Standard rank-based alternatives for non-linear correlations, such as Spearman rho, are available.