SPP1 and cancer: We hypothesised that various OCT4- and SPP1-transcript variants might be associated with the development and aggressiveness of various human somatic cancers; therefore, we comprehensively assessed the expression of these variants in healthy and cancerous human tissues in order to characterise their potential biological and clinical roles in human lung adenocarcinoma (LUAD), which is the leading cause of cancer-related deaths worldwide [31].