I am doing RNA-seq data analysis using hisat2 and stringTie. The purpose of my study is to search for genes that are differentially expressed between groups.

I have heard that hisat2 can add a read group by using the -rg option. I have not used the -rg option so far and have not experienced any problems. So I would like to ask, what is the significance of implementing -rg in hisat2? Would there be any inconvenience in performing a differential gene expression analysis without it? I would appreciate it if you could enlighten me.