Although DR5 and DR4, another major activating TRAIL apoptosis receptor, have relatively high homology (Chaudhary et al., 1997; Wiley et al., 1995) in the cysteine-rich domain and the death domain, the distribution and physiological functions of these two receptors in normal tissues and tumor tissues are significantly different. The gene discussed is TNFRSF10B; the disease is neoplasm.