Finding the culprit: who is turning hearts to stone?

A recent publication by Pillai et al. in the field of cardiac tissue mineralization has evoked a multitude of echoes in the press about turning hearts into bone or stone (1). Whilst the ‘turning into stone’ metaphor is not particularly novel, it has been effective in gaining public interest into this issue (2,3). Hardening the heart or turning hearts into stone, and ultimately healing it to transform them back into soft and compassionate organs of flesh, occurs in the literature through the centuries. Metaphors like this can be found from the Bible (4) to the Qur’an (5), from Shakespeare (6) to Hauff (7) and Wilde (8), all referring to turning a soft and tender heart into a rigid and unfeeling object. This analogy sits surprisingly well with the biological situation explored by Pillai et al. (1).