TACR1 and breast cancer: Importantly, this study showed that the impact of NK1R suppression on the growth and apoptosis of MDA‐MB‐231 cells was the same as that in MCF‐7 cells, which overexpress NK1R‐Tr These data suggest that the regulation of NK1R‐Tr by miR‐34b/c‐5p may be the main mechanism for inhibiting breast cancer cell growth.