Thirty years ago, archeologists excavated the tomb of an elite 40-50-year-old man from the Sicán culture of Peru, a society that predated the Incas. The man’s seated, upside-down skeleton was painted bright red. Researchers analysed the paint and found that in addition to a red pigment, it contains human blood and bird egg proteins. The study began when researchers wondered what the Sicán people had used in the paint mix as a binding material, which had kept the paint layer attached to the metal surface of the mask for 1,000 years. As per a release, the researchers analysed a small sample of the mask’s red paint. Using sophisticated equipment they found that the sample contained proteins, so proteomic analysis was done, which revealed six proteins from human blood in the red paint, including serum albumin and immunoglobulin G (a type of human serum antibody). Other proteins, such as ovalbumin, came from egg whites. Because the proteins were highly degraded, the researchers could not identify the exact species of bird’s egg used to make the paint, but a likely candidate is the Muscovy duck.