Using a genome-wide CRISPR screen (over 70,000 single guide RNAs) coupled with patient-derived metastatic BC cells, Ebright et al. [168] recently discovered that ribosomal genes, especially eL15, uL29 and eL13 (encoding RPL15, RPL35 and RPL13, respectively) were highly enriched in circulating tumour cells (CTCs). The gene discussed is RPL35; the disease is breast cancer.