The successes of first generation stem cell therapies must be matched against the failures - there is no shortage of failure in any new and dynamic field. Understanding how to best use stem cells to induce regeneration is an ongoing process, and our expectations of progress must be kept realistic. From Forbes: "Two German trials that used injected stem cells to strengthen the heart muscle after a heart attack got good results, while a small Norwegian trial showed no benefit. All three trials used stem cells derived from bone marrow. ... The injection fraction of the stem-cell recipients improved by 5.5 percent, compared to 3 percent for those who got conventional treatment ... After a year, the stem-cell recipients had a significantly lower incidence of second heart attacks. Their death rate was lower and fewer of them needed treatment to reopen blocked blood vessels. ... In sharp contrast, the Norwegian [study] showed no beneficial effect."