If you buy through a BGR link, we may earn an affiliate commission, helping support our expert product labs. Today, tattoos are so common that we don’t really even consider their significance.

The engineered tattoo cells produce melanin and darken when exposed to elevated calcium levels. This material relates to a paper that appeared in the 18 April, issue of Science Translational ...

Green tattoo pigment is taken up by dermal macrophages (left). The pigment is released when these cells are killed (center) but, 90 days later, is taken back up into new macrophages that have ...