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. 
As a mitochondrial P450 system, P450c11 is dependent on two electron transfer proteins, adrenodoxin reductase and adrenodoxin that transfer 2 electrons from NADPH to the P450 for each monooxygenase reaction catalyzed by the enzyme. In most respects this process of electron transfer appears similar to that of P450scc system that catalyzes cholesterol side chain cleavage.  Similar to P450scc the process of electrons transfer is leaky leading to superoxide production. The rate of electron leakage during metabolism depends on the functional groups of the steroid substrate. 
In an infant with a D-bifunctional protein deficiency ( 261515 ), van Grunsven et al. (1998) identified a 46G-A transition in the HSD17B4 gene, resulting in a gly16-to-ser (G16S) substitution within an important loop of the Rossman fold forming the NAD(+)-binding site. Biochemical analysis showed that the 3-hydroxyacyl-CoA dehydrogenase activity of the D-bifunctional protein was completely inactive, whereas the enoyl-CoA hydratase component was active. Their findings showed that the D-bifunctional protein plays an essential role in the peroxisomal beta-oxidation pathway that cannot be compensated for by the L-specific bifunctional protein. Both parents were heterozygous for the mutation.