APOA2 and cancer: When λ = 0.02359167, the error rate was minimized (Fig. 3A), and seven genes, namely, IL27, CD1D NCOA6, CTSE, FCGRT, CFHR1 and APOA2, were obtained, among which IL27 plays an important role in cancer and immunity (Fabbi, Carbotti & Ferrini, 2017), CD1D is a key factor in immunotherapy (King et al., 2018) and the homozygous deletion of CFHR1 is associated with acute myeloid leukemia (Fratelli et al., 2016).