Tumor malignancy identification plays an essential role in clinical management of cancer. Currently, biopsy is the gold standard for malignancy identification in most tumor cases, it is, however, invasive that can cause great discomfort to patients, and potentially increase the risk of distant metastases due to the complex sampling process. With the development of molecular imaging probes, non-invasive medical imaging approaches, such as magnetic resonance imaging (MRI), fluorescence imaging (FI), computed tomography, and ultrasound, etc., have been used for non-invasive tumor diagnosis. Nevertheless, majority of imaging strategies are often dependent on imaging probes that lack specificity for identification of tumor malignancy. Considering that necrotic cell death and overexpressed potassium ion (K) channels are major hallmarks of malignant tumors, but not for benign ones, the extracellular K concentration is significantly elevated in the malignant tumor microenvironment compared with that of benign tissue. Based on this, a new research led by Prof. Daishun Ling from Shanghai Jiao Tong University reported a K -sensitive dual-mode imaging probe (KDMN) to realize real-time tumor imaging while identifying the malignancy.