Hello.

I am doing DEGs using DESeq2. I am having difficulty drawing a heatmap after DEGs. There is no diffferneces in expression in my heatmap.

After pre-processing the count data, DEGs were processed. 'apply' function was used to create 'mat_scaled' dataframe.

Here is my heatmap. I think there should be differences in gene expression between 'Primary Tumor' and Solid Tissue Normal' in my heatmap.

How should I solve this problem?

It's not reproducible. Code lacking. Looks that the heatmap simply has no order such as hclust to show patterns. Please google for heatmaps after DEGs there are an extensive number of tutorials, for example ar biostars.org