A photo of a cyst nematode's head viewed through a high-power microscope shows its esophageal glands, which produce effectors it uses to infect host plants. The image was digitally edited to highlight ...

Pilonidal sinus—also called a pilonidal cyst—is a skin infection that occurs in or around the crease of your buttocks. This condition happens when hair, skin cells, and dirt clog a hair follicle, ...