Glyphosate: Pathways to Modern DiseasesGlyphosate is the active ingredient in the pervasive herbicide, Roundup. Its usage on crops to control weeds in the United States and elsewhere has increased dramatically in the past two decades. The increase is driven by the increase over the same time period in the use of genetically modified (GM) crops, the widespread emergence of glyphosate-resistant weeds among the GM crops (necessitating ever-higher doses to achieve the same herbicidal effect), as well as the increased adoption of glyphosate as a desiccating agent just before harvest. GM crops include corn, soy, canola (rapeseed), and sugar beet. Crop desiccation by glyphosate includes application to non-GM crops such as dried peas, beans, and lentils. It should be noted that the use of glyphosate for pre-harvest staging for perennial weed control is now a major crop management strategy. The increase in glyphosate usage in the United States is extremely well correlated with the concurrent increase in the incidence and/or death rate of multiple diseases, including several cancers. These include thyroid cancer, liver cancer, bladder cancer, pancreatic cancer, kidney cancer, and myeloid leukemia. The World Health Organization (WHO) revised its assessment of glyphosate's carcinogenic potential in March 2015, relabeling it as a "probable carcinogen."