We have previously shown that LINK‐A promoted breast carcinogenesis and malignant progression.[48, 49] To further investigate the in vivo roles of LINK‐A, especially in obesity, we constructed a LINK‐A KI mouse model to express human‐specific LINK‐A under the control of the mouse mammary tumor virus (MMTV)‐long terminal repeat (LTR) promoter[50, 51] using CRISPR/Cas9 KI technology (Figure 1d). Here, LINC01139 is linked to obesity due to melanocortin 4 receptor deficiency.