In his recent letter, Dr. presence of plasma EO per se has remained controversial [6]. New analytical studies and related findings are very relevant in this regard. For example, the use of high-performance liquid chromatography, coupled with offline multistage MS (MS2, and MS3), to examine the effects of pregnancy and of central angiotensin (Ang) II infusion on EO in rat plasma, led to the detection of EO and two other novel Chitosamine hydrochloride EO isomers [7,8]. These isomers have distinct chromatographic polarity compared to EO, while both have major MS2 and MS3 product ion spectra that are essentially indistinguishable from those of EO. Furthermore, both isomers bind to the anti-Ouabain antibody routinely employed in our radioimmunoassay (RIA), Chitosamine hydrochloride although affinity for the second isomer is at least an order of magnitude weaker that for EO. Both of these new isomers appear to be regulated independently from EO Chitosamine hydrochloride and may vary according to gender, age, and disease. Importantly, neither isomer was previously described nor is usually detectable in commercial sources of (herb) ouabain. Finally, recent work has confirmed that Chitosamine hydrochloride adrenal gland rat cells were able to produce and secrete EO compound [9]. The presence of EO in human plasma remains controversial, fuelled in part by Baecher et al. [10], who were unable to detect EO in human plasma using LC-MS. It is worth noting that the primary conclusion, as well as other circumstances surrounding the claim of Baecher et al., have been questioned [11,12]. Moreover, the plasma extracts used by Baecher and colleagues tested positive for EO with a well-documented Radiommunoassay (RIA) run in our laboratory [13,14]. These RIA data are significant because, in prior studies, EO continues to be consistently discovered once the same test ingredients had been put through LC-MS and LC-RIA [15,16]. Furthermore, the important analysis of the task performed on EO contains evidence from indie laboratories in a number of continents collected from 1990 to 2009, that is in keeping with an endogenous way to obtain endogenous ouabain [11] within the circulation. Beginning with 2009 [17,18,19], steroid biosynthesis, hereditary polymorphisms, and renal function have already been associated with EO in a number of clinical settings, especially with regard towards the previously proven genes involved with EO synthesis: the (LSS) gene polymorphism on the rs2254524 AA vs. CC [20]. LSS rs2254524 AA polymorphism was connected with: (1) a rise in the creation of EO after transfection in individual adrenal cells; (2) a rise of EO in renal tissues; and (3) a quicker loss of GFR regardless of similar degrees of blood circulation pressure [21]. These results are consistent with both (4) an increase in the incidence of Acute kidney Injury (AKI) after cardiac surgery [22] in patients transporting LSS rs2254524 AA polymorphism; and (5) podocyte damages after incubation with ouabain in animal models [23]. The latter evidence is prevented by the selective ouabain inhibitor, Rostafuroxin [24]. Finally, (6) in na?ve hypertensive patients Rostafuroxin normalizes Blood Pressure (BP) in LSS AA carriers, but it is usually inactive in CC carriers [20]. This is consistent with (7) specific data [25] showing the pressor effects of ouabain [26] in rats associated with the peculiar damage [27], and with (8) the presence of cell functional changes that are all prevented by Rostafuroxin [28]. These 8 groups of impartial findings gathered from rats and humans, both at the genetic cell and whole-body level, certainly ITGB2 substantiate the above data on EO plasma levels and are also relevant for establishing the scientific truth. Further evidence adding to the relationship between circulating EO and certain genetic polymorphisms (and highlighting this system as a target in the era of precision medicine) is usually under development [21]. In contrast to the in vivo cardio-protective effects of exogenous ouabain in rats, in our peer examined clinical studies we repeatedly observed that higher levels of circulating EO are associated with worsening outcomes among patients with cardiac and renal dysfunction. We should agree.