The MGBIG is a study exploring cross-generational effects in 5000 women and their children and grandchildren located in Guangzhou, China. Its initial aim is to facilitate research on understanding the interplay between genes and environmental factors on disease etiology and on explaining the cause of the disease from the perspective of grandmother-mother-child heredity. Data are collected regarding environmental exposures, lifestyle, and social support on grandmother from birth to old age. Biological samples including blood and tissue samples are collected.