similarity of transcriptome

Question

[biology_inform]

Hi all, I have analyzed many RNA-seq datasets taken from GEO and I analyzed all with same parameters and tools. Now I have many DGE lists. I wonder how to understand their transcriptome similarity and if I could is there a way to understand how are they similar with each other? In other words, how can I determine which gene/factor is responsible from this similarity?

Thanks in advance