Hello, I am very new to RNA-seq data and have no bioinformatics background. I have downloaded the TCGA data from cBioPortal. I would like to know about ‘data_RNA_Seq_v2_expression_median’. I presume they are absolute expression values. Why is it that for some tumors, the values are zero?
Can these values be converted to log scale for comparison of expression between different histologic subtypes of tumors (as for microarrays)? I would like to identify differentially expressed genes and generate heat maps from the expression data. How do I go about it and which software would be useful for this ?