It is also known that the NK-1 receptor is involved in the viability of the tumor cells, since following the application of a knockdown method (small interfering RNA gene-silencing (siRNA)), tumor cells die by apoptosis [14]: more apoptotic cells were observed in siRNA cells than in non- transfected cells and hence the number of siRNA tumor cells was significantly lower. This evidence concerns the gene TACR1 and neoplasm.