A protein in human sweat might help people ward off tick-borne Lyme disease, a new study published in Nature Communicationssays. Live Science and NBC News break down the findings, which center around the discovery of a genetic variant of the protein that appears to make people more susceptible. Best case: Down the road, this could theoretically lead to a topical cream people could apply—think “lyme block” instead of sunblock, as NBC puts it.A third genetic marker: Scientists previously knew of two other genetic variants that were linked with a higher risk of Lyme disease. But after analyzing e…