 Immediately adjacent to, and downstream of, each of these four "NOTCH" paralogs is an NBPF gene with its DUF1220 domains in the same orientation as its "NOTCH2NL" partner.This striking genomic arrangement suggests that each of the additional copies of "NOTCH2NL" that appeared in the human genome did not duplicate as a single gene, but rather did so as a two-gene module, composed of one "NOTCH2NL" gene and one "NBPF" gene.While the "NOTCH2NL" paralogs (and their "NBPF" partners) went from one gene to four in humans, DUF1220 copies encoded by these "NBPF" genes underwent human-specific hyper-amplification, increasing from 13 copies (encoded by "NBPF26") to 132 (i.e., adding 119 DUF1220 copies encoded by "NBPF10", "NBPF14" and "NBPF19").