Evangelina Villegas began their collaborative research in Mexico in the early 1970s while they were working at CIMMYT. Dr. Villegas was in charge of the lab investigating protein quality and Dr. Vasal was a plant breeder newly assigned to work on developing QPM varieties that would gain widespread acceptance. Integrating cereal chemistry and plant breeding techniques, Drs. Vasal and Villegas collaborated to combine the existing opaque-2 maize with genetic modifiers. Through the 1970s, they produced and analyzed germplasms at an astonishing rate, sometimes processing up to 25,000 samples a year. By the mid-1980s, they had produced a QPM germplasm with hard kernel characteristics and good taste similar to the traditional grain and with much higher quality levels of lysine and tryptophan. However, their discovery remained unexploited for years because many nutritionists felt that protein could be added to the diets of the most poor in other ways. In the early 1990s, CIMMYT gained the international support and funding to begin promoting QPM in Ghana and several other African countries. Since then, QPM has also yielded very positive results in China, Mexico, and parts of Central America. Genetics The opaque-2 mutation reduces the transcription of lysine-lacking zein-related seed storage proteins and, as a result, increased the abundance of other proteins that are rich in lysine. The lack of zein causes a soft texture, necessitating further development for "hard endosperm o.2" that lead to QPM. Impact Babies and adults consuming QPM are healthier and at lower risk for malnutrition disorders such as marasmus and kwashiorkor, and data from Latin America and Africa show the grain’s role in reversing the effects of malnutrition in those already affected. QPM offers 90% the nutritional value of skim milk, the standard for adequate nutrition value. At a time when UNICEF reports that 1,000,000 infants and small children are starving each month, the inclusion of QPM in daily rations improves health and saves lives. Additionally, pigs fed QPM experience rapid weight gain and are ready for market sooner or can provide an additional quality protein source for small farm families. QPM hybrids have been developed and tested for varying climatic and growing conditions; QPM varieties are grown on roughly 9 million acres (36,000 km²) worldwide. Meanwhile, QPM research and development have spread from Mexico to throughout Latin America and to Africa, Europe, and Asia. In Guizhou, the poorest province in China, QPM hybrid yields are 10% higher