Notably, changes were not detected in the expression of UNC5H4 in the remaining 7/20 cases, including 3 squamous cell carcinoma and 4 adenocarcinoma cases (1 well-, 5 moderately- and 1 poorly-differentiated), however, significant increases in caspase 3 protein activation levels were observed (Fig. 4A and B), but were shown to be significantly lower when compared with those of the 13 NSCLC cases with increased UNC5H4 expression (P<0.05; Fig. 4C). Here, CASP3 is linked to squamous cell carcinoma.