Growth of MADB106 mammary tumor in rats maintained on diets of varying folate content. After 6 weeks on the dietary conditions indicated, tumor cells were injected subcutaneously into six animals per group. Tumor volumes were measured by calipers. Insert: Tumor volume and day plotted on natural log scales. At a significance level of 5%, the slopes for the high folate diet were larger than the low and very low folate diets, but not the folate replete diet. The slopes for the folate replete diet were larger than the low folate diet, but not the very low folate diet. The slopes for the very low folate diet were larger than the low folate diet as a group.