An important percentage of colorectal cancer(CRC) patients will develop metastasis,mainly in the liver,even after a successful curative resection.This leads to a very high mortality rate if metastasis is not detected early on.Disseminated cancer cells develop from metastatic stem cells(Met SCs).Recent knowledge has accumulated about these cells particularly in CRC,so they may now be tracked from the removed primary tumour.This approach could be especially important in prognosis of metastasis because it is becoming clear that metastasis does not particularly rely on testable driver mutations.Among the many traits supporting an epigenetic amplification of cell survival and self-renewal mechanisms of Met SCs,the role of many immune cell populations present in tumour tissues is becoming clear.The amount of tumour-infiltrating lymphocytes(T,B and natural killer cells),dendritic cells and some regulatory populations have already shown prognostic value or to be correlated with disease-free survival time,mainly in immunohistochemistry studies of unique cell populations.Parallel analyses of these immune cell populations together with Met SCs in the primary tumour of patients,with later follow-up data of the patients,will define the usefulness of specific combinations of both immune and Met SCs cell populations.It is expected that these combinations,together to different biomarkers in the form of an immune score,may predict future tumour recurrences,metastases and/or mortality in CRC.It will also support the future design of improved immunotherapeutic approaches against metastasis. An important percentage of colorectal cancer (CRC) patients will develop metastasis, mainly in the liver, even after a successful curative resection. This leads to a very high mortality rate if metastasis is not detected early on. Disseminated cancer cells develop from metastatic stem cells (Met SCs) .Recent knowledge has accumulated about these cells particularly in CRC, so they may now be tracked from the removed primary tumor. This approach could be particularly important in prognosis of metastasis because it is becoming clear that metastasis does not specifically rely on on testable driver mutations. Amy the many traits supporting an epigenetic amplification of cell survival and self-renewal mechanisms of Met SCs, the role of many immune cell populations in tumour tissues is becoming clear. amount of tumor-infiltrating lymphocytes (T, B and natural killer cells), dendritic cells and some regulatory populations have already shown shown prognostic value or to be correlated with disease-free su rvival time, primarily in immunohistochemistry studies of unique cell populations. Parallel analyzes of these immune cell populations together with Met SCs in the primary tumor of patients, with later follow-up data of the patients, will define the usefulness of of specific combinations of both immune and Met SCs cell populations. It is expected that these combinations, together to different biomarkers in the form of an immune score, may predict future tumor recurrences, metastases and / or mortality in CRC. Will also support the future design of improved immunotherapeutic approaches against metastasis.