A renal tubule is a tube that filters, re-absorbs and secretes substances to rid an organism of waste and to play a role in fluid homeostasis. [ http://dx.doi.org/10.1371/journal.pone.0099864 GOC:dph GOC:mtg_kidney_jan10 http://amigo.geneontology.org/amigo/term/GO:0061333 ]