CD47 and head and neck squamous cell carcinoma: Expression of the mRNAs encoding the CD8 coreceptor subunits and the CD47-dependent activation markers CD69 and TNFα was positively correlated with mRNA expression of MYCN in head and neck squamous cell carcinoma, breast invasive carcinoma, prostate carcinoma, and lung squamous cell carcinoma, but no significant correlations between MYCN mRNA and overall survival were observed for these cancers.