This cell dependent effect is expected given that Igf1r is often overexpressed in breast cancers [14,15] and analyses using databases such as Oncomir and dbDEMC, which have compiled expression data of miR in tumor and normal tissue from patients, showed that miR-15b is upregulated in invasive carcinoma and in other breast cancer subtypes compared to normal tissue [93]. Here, IGF1R is linked to breast cancer.