CHRM1 and malignant colon neoplasm: Second, M3R protein expression was significantly greater than M1R expression in both adenomas (Figure 1D) and adenocarcinomas (Figure 1F); in both adenomas and adenocarcinomas, M3R staining intensity was approximately two-fold greater than that for M1R. Third, in contrast to our findings for M3R expression, compared to expression levels in primary colon cancers, M1R expression remained increased in lymph node and liver metastases (Figure 1H,J).