to the generation of patient specific iPSCs, in most clinical approaches, it is nearly indispensable to harvest cells directly from the affected patient. Most commonly, normal human dermal fibroblasts are obtained either from adult skin biopsies or neonatal foreskin biopsies from circumcisions. In case of adult patients, dermal fibroblasts can be established from a skin punch biopsy with the common punch size of 3.5 or 4 mm. This method is very painful; hence, the selected position, mostly located at the arm, has to be anaesthetized. Secondary effects of skin punch biopsies are small bleedings and punch biopsies with a big diameter have to be stitched [45]. Furthermore, a certain risk of infection, allergic reactions to the anesthetic, and the formation of scar tissue or keloids are present. Taken together, a skin biopsy is not a simple intervention and has to be supervised and performed by medical professionals.
