FIG 2.

Distribution of cancer-related HERV papers by cancer type. A total of 2,735 full-text HERV-related papers were searched for cancer-related keywords. Articles with ≥0.2% of all words being general cancer keywords were considered cancer related. The resulting 655 cancer-related primary research HERV articles were probed for the cancer type that was mentioned most often and divided into one of 26 cancer categories, including nonhuman cancers and a “multiple cancer” category. Nonhuman cancers were included for completeness.