Disclosed herein are methods of increasing numbers of monocytes to a tumor or cancer metastasis site in a subject. Non-limiting embodiments include administering or using a Nur77 polypeptide or subsequence thereof; a Nur77 agonist; a CX3CR1 agonist; CD14+ CD16+ monocytes and/or CD14dimCD16+ (CD115+CD11b+ GR1− (Ly6C−)) monocytes; CD14+ CD16+ monocytes and/or CD14dimCD16+ (CD115+CD11b+GR1− (Ly6C−)) monocytes contacted with a Nur77 agonist or contacted with a CX3CR1 agonist. Also disclosed herein are methods of increasing, stimulating, activating or promoting monocyte migration to or mobilization against a tumor or cancer metastasis in a subject. Non-limiting embodiments include administering a Nur77 polypeptide or subsequence thereof; a Nur77 agonist; a CX3CR1 agonist; CD14+ CD16+ monocytes and/or CD14dimCD16+ (CD115+CD11b+GR1− (Ly6C−)) monocytes; or CD14+ CD16+ monocytes and/or CD14dimCD16+ (CD115+CD11b+GR1− (Ly6C−)) monocytes contacted with a Nur77 agonist or contacted with a CX3CR1 agonist.