PLAC9 and neoplasm: Interestingly, of the few genes that, via sPLS-DA, were predicted to contribute to tumor regression at certain stage-to-stage interfaces—including DAPK2, PLAC9, ABCB9, MELTF, CTHRC1, and OCIAD2, testing for LUAD patient survivability via AK4 combination resulted in a negative prognosis.