Fig. 3
From: Piwi-interacting RNAs in cancer: emerging functions and clinical utility
Number of piRNA-related publications per year. Search was performed within EndNote (version 7, Thomson Reuters) and manually filtered. Number of entries are based on a United States National Library of Medicine (NLM) PubMed search using the terms “piRNA OR PIWI-interacting RNA” (blue line) or “piRNA OR PIWI-interacting RNA AND cancer” (red line) and annual (Jan 1-Dec 31) date limitations. 2015 publications were not included in the search