CBX5 and cancer: However, due to the close proximity, it must be taken into account that an element affecting the transcriptional activity of CBX5 could also affect the activity of hnRNPA1. Despite the bi-directional promoter structure, no overall significant correlation in expression pattern is observed between CBX5 and hnRNPA1 in the NCI-60 cancer cell line panel (correlation coefficient 0.129) (Fig. 1b and Additional file 3: Figure S1).