The image above is a close-up of the tip of an intestinal villus, where one can see goblet cells (yellow) actively sampling their environment. Some goblet cells have perfect overlap of yellow and purple signal. This is called a “goblet cell-associated antigen passageway,” or a “GAP.” These goblet cells connect with immune cells (cyan), which can then migrate to lymph nodes and educate the immune system on what it just sampled. These phenomena have implications in food allergy, tolerance, and immunity. The image was taken by 2025 Summer Scholar Jenna Kramer, who Freed mentored.