Itty-bitty seeds of human stomachs can now bud in plastic dishes. By bathing stem cells in a brew of growth-boosting chemicals, scientists have kick-started the constructionof crude organs about as bigas the head of a pin. These primitive balls of gastric tissue — the first to be cooked up in the lab — resemble the stomachs of developing fetuses. The lab-grown bellies represent the latest in a line of do-it-yourself organlike cell clumps, including livers, brains and guts Three years after figuring outhow to transform stem cells into human intestinal tissue, and more recently, how to make that tissue grow in mice (SN Online: 10/19/14), developmental biologist James Wells of Cincinnati Children’s Hospital Medical Center and colleagues have monkeyed with their method to make 3-D stomachlike organs. Like human stomachs, the lab-grown globs contain both mucus-making and hormone-pumping cells. Thetissue also mimics a stomach’s response to infection withHelicobacter pylori. The ulcer-causing bacteria cue the globs to switch on the same molecular signals that real stomach cells use, Wells andhis team reportOctober 29 inNature. The mini stomachs hand researchers a new tool for studying gastric human disease, including cancer, the researchers suggest.