Acts upstream of or within several processes, including Kupffer's vesicle development; cilium assembly; and determination of left/right symmetry. Located in nucleus. Is expressed in several structures, including axial chorda mesoderm; forebrain neural rod; midbrain hindbrain boundary; otic placode; and tail bud. Human ortholog(s) of this gene implicated in colorectal cancer and hepatocellular carcinoma. Orthologous to human IER2 (immediate early response 2).