Using sunscreen is one of the most effective ways to defend your body against harmful UVs [1], but turns out, skin cancer could be lurking in places you wouldn't even think to apply SPF. Researchers say [2] melanoma can be found on the soles of the feet due to damage from walking or running.

How can you get skin cancer [3] on a place that rarely sees the sun? "Our clinical observation suggests that mechanical stress — such as plantar pressure and shear stress — is involved in the development of melanoma on the sole," senior researcher Dr. Ryuhei Okuyama of Shinshu University School of Medicine in Matsumoto, Japan, told Health Day. "Plantar" areas include places that receive the most pressure like the heel, ball of the foot, and side foot arch.

Although rare (especially under the feet), melanoma can be a deadly form of cancer, and most patients with it on their soles discover it in its advanced stages. According to the study, the average age of those with this rare cancer was 73.5 years.

Consider adding a sole check to your routine screening, and look for any signs of melanoma such as moles, unusual coloration, or any other irregularities that change in size and shape.