PCSK9 and cancer: Other cancers exhibited a protective role for PCSK9 with low expression, such as BRCA (OS, HR = 0.58, p = 0.001; RFS, HR = 0.64, p = 0.047), UCS (OS, HR = 0.61, p = 0.022; RFS, HR = 0.56, p = 0.044), ESCA (RFS, HR = 0.26, p = 0.013), and HNSC (RFS, HR = 0.26, p = 0.007).