We speculate the following: 1) despite the low plasma renin level, DOCA mice may upregulate macrophage local RAS, such as the upregulation of AT1R, which is similar to our previous findings in hypertensive DS rats (Zhou et al., 2003; Zhou et al., 2006) 2) the results from the present study may apply to DOCA hypertension or SS hypertension, and whether the results can apply to other hypertension remains to be confirmed. Here, REN is linked to Hypertension.