Hi all, I'm having a hard time understanding a concept in bioinformatics. So right now, I'm learning FPKM values. I'm not sure why we need this value in the first place. What is importance and what does it tell you that raw count data don't?

Also, why do we need to normalized the data? I don't quite understand the point of normalization. What is the difference between normalized data and un-normalized data?

Thank you so much!

Perhaps you should do some reading of the RNA-seq normalization literature:

• https://dx.doi.org/10.1186/gb-2010-11-3-r25 for the TMM paper
• https://dx.doi.org/10.1186/gb-2010-11-10-r106 for DESeq size factors
• http://www.rna-seqblog.com/rpkm-fpkm-and-tpm-clearly-explained

There's probably more that I haven't listed, but a quick Google should fill the gaps.