Fig. 2
Strategy to explore the contribution of genetic and environmental factors on variation in cancer risks. a The construction of the ranked lifetime cancer risk (LCR) matrix. Part 1: The 423 × 17 original LCR matrix using global-wide data for 17 cancer types in 423 registries in 68 different countries. For the jth column in the matrix, the color from dark blue to dark red represents the LCR of cancer j ranges from the lowest to the highest in 423 registries, and it can also indirectly denote the EH in 423 registries of cancer j ranged from the best to the worst. Part 2: The ranked LCR matrix, constructed by sorting the LCR in each column (each cancer) in the original LCR matrix from the lowest to the highest. We denote the level of EH (row) in the ranked LCR matrix as EHlat, i.e., the first row of the ranked LCR matrix is regarded as the optimal EHlat of all 17 cancers in 423 registries, followed by the second optimal EHlat, until to the worst EHlat. b For the ith EHlat (row) in the ranked LCR matrix, the LCRi attributes to the ith LSCDi, which is caused by the ith EHlat i. However, the true number of stem cell divisions under each EHlat (\(LSCD_{1} , \cdots ,LSCD_{{{423}}}\)) cannot be observed, we can only obtain LSCD0 under the laboratory environment. Dotted grey nodes represent the unmeasured variables