POSTN and cancer: Recently, it has been reported that periostin plays an important role in tumorigenesis of a wide variety of cancers, such as non-small-cell lung cancer [15], colorectal cancer [16], head and neck cancer [17], ovarian cancer [18], pancreatic cancer [19], penile cancer [20], prostate cancer [21], hepatocellular carcinoma [22], and cholangiocarcinoma [23].