Xenotransplantation in the context of "Humanized mouse"

Life extension is the concept of extending the human lifespan, either modestly through improvements in medicine or dramatically by increasing the maximum lifespan beyond its generally-settled biological limit of around 125 years. Several researchers in the area, along with "life extensionists", "immortalists", or "longevists" (those who wish to achieve longer lives themselves), postulate that future breakthroughs in tissue rejuvenation, stem cells, regenerative medicine, molecular repair, gene therapy, pharmaceuticals, and organ replacement (such as with artificial organs or xenotransplantations) will eventually enable humans to have indefinite lifespans through complete rejuvenation to a healthy youthful condition (agerasia). The ethical ramifications, if life extension becomes a possibility, are debated by bioethicists.

The sale of purported anti-aging products such as supplements and hormone replacement is a lucrative global industry. For example, the industry that promotes the use of hormones as a treatment for consumers to slow or reverse the aging process in the US market generated about $50 billion of revenue a year in 2009. The use of such hormone products has not been proven to be effective or safe. Similarly, a variety of apps make claims to assist in extending the life of their users, or predicting their lifespans.

A human–animal hybrid (or animal–human hybrid) is a hypothetical organism that incorporates elements from both humans and non-human animals. In a technical sense, a human–animal hybrid would be defined as an organism in which each cell contains both human and non-human genetic material. This contrasts with a non-human chimera in which some cells are human and the other are derived from a non-human organism (a human chimera, by contrast, consists entirely of human cells from different zygotes.)

Examples of human–animal hybrids mainly include humanized mice that have been genetically modified by xenotransplantation of human genes. Humanized mice are commonly used as small animal models in biological and medical research for developing human therapeutics.

Life extension is the concept of extending the human lifespan, either through incremental improvements in medicine or through radical increases in maximum lifespan beyond its generally-settled biological limit of around 125 years. This field of study has been explored by numerous researchers and advocates, including "life extensionists", "immortalists", and "longevists" (those who aspire to achieve prolonged lifespans themselves). These researchers and advocates hypothesize that future advancements in tissue rejuvenation, stem cells, regenerative medicine, molecular repair, gene therapy, pharmaceuticals, and organ replacement (such through artificial organs or xenotransplantations) will eventually enable humans to have indefinite lifespans through complete rejuvenation to a state of optimal health and youth (agerasia). The ethical implications of life extension are a subject of discourse among bioethicists.

The sale of purported anti-aging products, such as supplements and hormone replacement therapy, is a lucrative global industry. For example, the industry that promotes the use of hormones as a treatment for consumers to slow or reverse the aging process in the US market generated about $50 billion of revenue a year in 2009. The use of such hormone products has not been proven to be effective or safe. Similarly, a variety of apps make claims to assist in extending the life of their users, or predicting their lifespans.

Patient derived xenografts (PDX) are models of cancer where the tissue or cells from a patient's tumor are implanted into an immunodeficient or humanized mouse. It is a form of xenotransplantation. PDX models are used to create an environment that allows for the continued growth of cancer after its removal from a patient. In this way, tumor growth can be monitored in the laboratory, including in response to potential therapeutic options. Cohorts of PDX models can be used to determine the therapeutic efficiency of a therapy against particular types of cancer, or a PDX model from a specific patient can be tested against a range of therapies in a 'personalized oncology' approach.