Plays a role in neuronal and neurobehavioral development (PubMed:31623237). Required for normal expression of the postmitotic and mature neuron markers elavl3 and eno2 and neurobehaviors related to circadian rhythm and altered light-dark conditions (PubMed:31623237). Highly expressed in the gut, myotomes and brain, especially the midbrain and hindbrain, at 3 days post-fertilization (dpf). Double knockout of c3orf70a and c3orf70b resulted in significantly decreased expression of the mature neuron markers elavl3 and eno2 and the midbrain/hindbrain marker irx3b. Neurobehaviors related to circadian rhythm and altered light-dark conditions were significantly impaired. Belongs to the UPF0524 family.