While previous studies have examined breast cancer samples with respect to RB1 LOH, loss of pRb immunostaining [3] and chromosomal rearrangements [7], except for one study reporting no mutations when sequencing the exon 21 only [27] and the finding of point mutations in a single breast cancer cell line [8], we are not aware of any study reporting RB1 point mutations in breast cancer tissue http://rb1-lsdb.d-lohmann.de/. Here, RB1 is linked to breast cancer.