Scientists have discovered that a gene normally considered a DNA-protecting "good guy" can become dangerous when cells make too much of it. The gene, EXO1, acts like molecular scissors that help repair DNA, but when overproduced it starts cutting DNA it shouldn't, creating damage linked to cancer.

Scientists have discovered that a gene normally considered a DNA-protecting "good guy" can become dangerous when cells make too much of it. The gene, EXO1, acts like molecular scissors that help repair DNA, but when overproduced it starts cutting DNA it shouldn't, creating damage linked to cancer.