At the time of submission, database mining of available cancer cell lines in the COSMIC database (http://cancer.sanger.ac.uk/cosmic/) failed to identify any other line with the p.R215W mutation, and also did not reveal any other breast cancer cell line with a coding NBN mutation, so that HCC1395 may provide a unique source for studying the molecular consequences of NBN deficiency. The gene discussed is NBN; the disease is cancer.