良性

positive (in its effect) / leading to good consequences / virtuous / (medicine) benign (tumor etc)

good / very / very much

nature / character / property / quality / attribute / sexuality / sex / gender / suffix forming adjective from verb / suffix forming noun from adjective, corresponding to -ness or -ity / essence / CL:個|个[ge4]

benign tumor

aplastic anemia

virtuous cycle (i.e. positive feedback loop)