A statue of Vlad the Impaler shown next a letter written by him in 1457. Scientists think traces of proteins found on the letter point to the ruler having had a condition that could mean he shed tears of blood.
David Greedy/Getty Images; Pittalà MGG. et al, Analytical Chemistry, 2023, DOI: 10.1021/acs.analchem.3c01461/Insider.