Upper row: Confocal micrographs of Drosophila eye imaginal disc epithelium (left and middle: xy sections, right: xz cross-section) carrying GFP-marked clonal tumors (green). Cell outlines are visualized with antibodies against Fasciclin III (blue) and DE-cadherin (red). Clonal activation of the Jun-N-terminal kinase (JNK) signaling pathway induces apoptosis and extrusion of dying cells from the e…