PTHLH and breast carcinoma: Parathyroid hormone-related protein (PTHrP) was reported to not only increase transcriptional activity of the integrin subunit α5 (Anderson et al. 2007) but also upregulate integrin α6β4 expression and activate Akt in breast cancer cells (Dittmer et al. 2006; Shen and Falzon, 2006; Shen et al. 2007).