I have a small confusion about running humann_regroup table.
I successfully executed humann (version3), normalised the results of my run using humann_renorm_table and concatenated the output using human_join_tables.
Looking at the help file of humann_regroup table I see that the only options that I have are uniref90_rxn and uniref50_rxn.
Can you tell me it there is a difference between uniref90_rxn and uniref90_level4ec?
If yes can you explain what it is and how can I obtain uniref90_level4ec?
Thank you very much in advance for your time.
PS: can you also explain what humann_reduce_table does exactly as I can not understand if i need to use it or not? I could open another topic for that if you like.