The invention discloses an application of POU5F1B in diagnosis, treatment, prognosis and relapse prediction of tumor. In the invention, it is found that the copy number and the expression level of the
gene POU5F1B in various tumors are closely related to transfer, relapse, patient prognosis and
dryness of the
tumor cells. A
research result proves that by means of high expression of the POU5F1B, formation of TIC is promoted and further the in-vivo tumorigenic capability of
esophagus cancer cells is enhanced, thereby reducing the
survival rate, and oppositely, by means of inhibition of the expression of the POU5F1B, the formation of the TIC is promoted and further the in-vivo tumorigenic capability of the
esophagus cancer cells is reduced, thereby increasing the
survival rate, so that it is obviously that by means of inhibition of the endogenous POU5F1B, the in-vivo tumorigenic capability of the
esophagus cancer cells can be significantly reduced, thereby increasing the
survival rate of patients, which proves that the POU5F1B can be used as a marker for diagnosis, treatment, prognosis and relapse prediction. An inhibitor of the POU5F1B has a great clinical application value in preparation of a
drug composition for tumor, so that the invention provides a new
drug and a new method for
effective treatment of tumor.