Stop codon suppression or translational readthrough occurs when in translation a stop codon is interpreted as a sense codon, that is, when a (standard) amino acid is 'encoded' by the stop codon. Mutated tRNAs can be the cause of readthrough, but also certain nucleotide motifs close to the stop codon. Translational readthrough is very common in viruses and bacteria, and has also been found as a gene regulatory principle in humans, yeasts, bacteria and drosophila.   This kind of endogenous translational readthough constitutes a variation of the genetic code , because a stop codon codes for an amino acid. In the case of human malate dehydrogenase , the stop codon is read through with a frequency of about 4%.  Amino acids inserted at the stop codon depends of the identity of the stop codon itself: Gln, Tyr and Lys; have been found for UAA and UAG codon, while Cys, Trp, Arg for UGA codon have been identified by mass spectrometry. 
When tested in vitro , 7-keto appears to activate the beta subset of the estrogen receptor (ERβ) with an EC 50 around 500μM which is partially blocked by exemestane (aromatase inhibitor or AI); there was no apparent activity on the classical subset (ERα) and parent DHEA and DHEAS were eqipotent.  As activity was hindered with an AI and there was efficacy in HepG2 cells but not Hep293 (expressing  and not expressing  aromatase, respectively) it is though that 7-oxo can be metabolized into an estrogen.