In a mouse model of liver implantation of MHCC97L cells in which the development of liver tumors was monitored weekly by bioluminescence imaging (Figure S5A–C, Supporting Information), the level of NID1 in circulating EVs was higher in tumor‐bearing mice than in mice prior to tumor cell inoculation and increased with the intensity of bioluminescence (Figure 3G and Figure S5, Supporting Information). Here, NID1 is linked to neoplasm.