Silencing of CCNE1, PLEKHF1, POP4, ZNF536 and TSHZ3 expression selectively reduced cell viability in cancer cells harbouring 19q12 gene amplification but had a significantly lower impact on the survival of breast cancer cells lacking amplification of this locus (t-test P < 0.05; Figure 2). The gene discussed is POP4; the disease is breast carcinoma.