In order to determine whether this tumour initiating potential was re-acquired from the surviving (post-treatment) cell population, TRAIL/FLIPi treated cultures - with no residual mammosphere forming ability (Figure 6B, Treatment 1) - were maintained in adherent culture for four weeks then transferred to mammosphere culture or re-treated with TRAIL/FLIPi (Figure 6B, Treatment 2). The gene discussed is TNFSF10; the disease is neoplasm.