In a post to Facebook, Jean Skinner shared a picture of what she says is a sign of melanoma.

The story goes like this: Skinner was working at a nail salon when a woman came in to ask of they could put a polish dark enough to cover up a mark she had on her nail. As soon as Skinner saw the mark, she knew that it was a sign of melanoma.

The customer went to a doctor and it was confirmed: melanoma. The customer's outlook is grim, though, as, according to Skinner, the cancer had already spread to the lymph nodes.

Skinner goes on to ask everyone to pay attention to any marks or discolorations in the bed of their fingernails, as they could signs that their body is trying to tell them something!