In summary, knockdown of key ribosome biogenesis factors (PPAN, NPM, SBDS and PES1) or alternatively interference with RNA pol I function by depletion of the transcription factor UBF-1 or pharmacological inhibition by CX-5461 increased expression of the autophagy related genes ATG7 and ATG16 L1 in cancer cells. Here, PPAN is linked to cancer.