NRXN1 and neoplasm: The patterns of exon deletions support the proposed roles for some of these genes in human disease, such as NRXN1 and PARKIN, and suggest limited roles or no role at all, for others, including MACROD2 and CTNNA3. Our results also offer an alternative interpretation for the observations of deletions in tumors which have been proposed as reflecting tumor-suppressive activity of genes in these hotspots.