LIFR and breast cancer: It has further been reported that PTHrP affects breast cancer growth by binding to and suppressing the expression of leukemia inhibitory factor receptor (LIFR), a cytokine receptor known to inhibit cancer cell differentiation via activation of signal transducer and activator of transcription (STAT3) of the Janus kinase signal transducer and activator of transcription (JAK-STAT) [74].