We investigated the utility of diffusion time-dependence of ADC measurements for the differentiation of prognostic biomarkers in human breast tumors using OGSE and PGSE sequences. Malignant tumors had significantly lower ADC values with longer diffusion times. ADC change significantly correlated with Ki-67 expression. Significant association was found between ADC value (at the effective diffusion time of 5.1ms) and PgR expression. These associations indicate the potential of the diffusion-time-dependent ADC values as a tool to differentiate these prognostic biomarkers and highlight tumor heterogeneity without the need of contrast agents.