MXRA8 and breast cancer: To determine whether the loss of MXRA8 expression regulated mammary tumor initiation, growth, or metastasis, 1 × 106 231MXRA8Con, 231MXRA8KO-O, or 231MXRA8KO-V cells were injected into the fourth mammary gland of NCG mice (NOD-Prkdcem26Cd52Il2rgem26Cd22/NjuCrl, Charles River, Wilmington MA, USA).