Even though the fact that Let-7 miRNAs function as tumor suppressors[38–39] by suppressing oncogene ras, we did not notice significantly different expressions of kras, hras and nras in KS biopsies in our previous studies, implying the involvement of alternative mechanisms in the let-7 related regulation of latency-replication switch. The gene discussed is HRAS; the disease is Kaposi's sarcoma.