part of start stage end stage margin noninvoluting endocytic marginal cell cluster TAO:0001126 noninvoluting endocytic marginal cells zebrafish_anatomy The NEM cell cluster lies in a superficial position of the dorsal blastoderm margin encompassing EVL cells and one or two layers of underlying deep cells. Unlike other marginal blastomeres, cells in this cluster do not participate in involution. ZFA:0001126 NEM portion of tissue unknown gastrula:50%-epiboly