Supporting this, CTSB itself as well as M6PR (mannose-6 phosphate receptor) that is essential for the lysosomal localization of CTSB and other lysosomal hydrolases1, RAB29 that is responsible for recycling M6PR back to Golgi apparatus47, and MZF1 (myeloid zinc finger 1) transcription factor that enhances CTSB and cathepsin L (CTSL) transcription48, were among the 572 genes whose depletion resulted in severe mitotic defects in a previously published, genome-wide, image-based siRNA screen for mitosis regulators in HeLa cervix carcinoma cells (http://www.mitocheck.org)49. The gene discussed is CTSL; the disease is cervical carcinoma.