RELN and cancer: The decrease in the abundance of genus Prevotella 2 was significantly associated with the decreased expression of MT1M in cancer tissues (r = − 0.999, p-value = 0.001, df = 2; Table 2); the positive abundance change of family Halomonadaceae was significantly associated with the reduction in the expression level of RELN (r = 0.957, p-value = 0.043, df = 2; Table 2).