a-b, Distribution of APOE carrier status in the Atherosclerosis Risk in Communities study (ARIC) and the MDACC melanoma study before (a) and after (b) imputation of APOE genotype (P < 2.2 × 10−16 and P = 1.82 × 10−11, respectively; χ2 test). c-g, Survival of melanoma patients in the MDACC study stratified by local melanoma stage and APOE genotype (two-sided log-rank tests). h, Survival of stage II/III melanoma patients in the MDACC and TCGA-SKCM studies (two-sided log-rank test). i-k, Distribution of age (i), melanoma Clark level (j), and sex (k) in stage II/III patients of the MDACC and TCGA-SKCM melanoma studies (respective significance tests: P = 6.42 × 10−9, Kruskal-Wallis rank sum test; P = 0.0005, χ2 test; P = 0.052, χ2 test). Hinges of boxplots represent the first and third quartiles, whiskers extend to the smallest and largest value within 1.5 × interquartile ranges of the hinges, and points represent outliers.