Homozygous Vps28^A2 mutant tissue partially survives in mosaic eye discs, and is not completely 'out-competed'. Although mutant ommatidia are not recovered, the wild-type ommatidia composing the adult eyes of mosaic animals are variably overgrown.

Vps28^A2 mutants exhibit neoplastic tumours.

Compared with wild-type, egg chambers containing Vps28^A2 mutant cells exhibit a loss of plasma membrane, ultimately leading to the formation of clusters of multinucleated cells enclosed by a single actin cytoskeleton, with nuclei rested around clumps of actin-positive structures, possibly also membrane fragments.