Here’s what you’ll learn when you read this story:Researchers have found that serum from younger blood can be combined with bone marrow cells and injected into older skin cells, producing rejuvenating effects. Extracting serum from more youthful skin and combining it with bone marrow cells actually showed visible effects on skin cultures in vitro. The researchers concluded that there must be an interaction between blood and bone marrow cells that causes skin rejuvenation. Without the bone marrow cells, the serum had no effect (which explains why vampire facials are more hype than anything else). Hematopoietic stem cells (HSCs), found in both blood and bone marrow, are immature cells that can develop into all types of blood cells and self-renew, making them a huge asset for regenerative medicine.