AXL and neoplasm: The inverse correlation between expression levels of AXL and PTBP1 in normal vs. tumor (GSE10072: r = −0.60, P < 0.001; GSE27262: r = −0.63, P < 0.001) and normal vs. adenocarcinoma (ADC) (GSE10245: r = −0.40, P < 0.01; GSE8894: r = −0.34, P < 0.007) were observed as shown in Fig. 7a,b, respectively.