Immunohistochemical Analysis of YAP1 and NMU in Pancreatic Cancer

A TMA for pancreatic cancer was purchased from US Biomax (PA721a, Rockville, MD, USA) and immunostained with anti-YAP1 (#12395, Cell Signaling) and anti-NMU (NMU41-A, Alpha Diagnostics International Inc., San Antonio, TX, USA) antibodies using a Dako REAL EnVision Detection System (Dako) following the manufacturer’s instructions. The cutoff value was defined on the basis of the method reported by Li et al. [53 (link)] with slight modifications, such as using the expression range 0–5 to divide samples according to low and high expression of YAP1 and NMU. All scores were evaluated separately; the mean calculated score was used to represent the immunoreactivity of the tumor. The correlation between YAP1 and NMU was evaluated by Pearson’s correlation, and the association between ordinal variables was assessed.