Some investigators reported that variants involving the ATP-binding cassettes (ABC) of MRP2 protein and those resulting in severely dysfunctional or absent protein (like splicing, truncating, and frameshift variants) were more common in patients with neonatal-onset DJS, whereas variants involving domains other than the ABC of the MRP2 protein were commonly observed in adults (9, 11). The gene discussed is ABCB6; the disease is Dubin-Johnson syndrome.