More potent for use in blood doping is Co 2+ (administered as Cobalt(II) chloride , CoCl 2 ). Cobalt chloride has been known to be useful in treating anemic patients.   Recent experimental evidence has proved the efficacy of cobalt chloride in blood doping.  Studies into the action of this species have shown that Co 2+ induces hypoxia like responses, the most relevant response being erythropoiesis. Co 2+ induces this response by binding to the N-terminus (loop helix loop domain) of the Hypoxia inducing transcription factors HIF-1α and HIF-2α, and thus stabilizes these protein complexes.   Under normal O 2 conditions, HIFs are destabilized as proline and asparagine residues are hydroxylated by HIF-α hydroxylases, these unstable HIFs are subsequently degraded following a ubiquitin-proteosome pathway, as such, they cannot then bind and activate transcription of genes encoding Erythropoietin (EPO).   With Co 2+ stabilization, degradation is prevented and genes encoding EPO can then be activated. The mechanism for this Co 2+ N terminus stabilization is not yet fully understood. In addition to N-terminus binding, it has also been hypothesized that replacement of Fe 2+ by Co 2+ in the hydroxylase active site could be a contributing factor to the stabilizing action of Co 2+ .  It is understood however, is that Co 2+ binding permits Ubiquitin binding but prevents proteosomal degradation. 
Some children grew up inside the walls of Unit 731, infected with syphilis. A Youth Corps member deployed to train at Unit 731 recalled viewing a batch of subjects that would undergo syphilis testing: "one was a Chinese woman holding an infant, one was a White Russian woman with a daughter of four or five years of age, and the last was a White Russian woman with a boy of about six or seven."  The children of these women were tested in ways similar to their parents, with specific emphasis on determining how longer infection periods affected the effectiveness of treatments.