CD22 and neoplasm: Related research has shown that in patients who relapsed due to diminished tumor CD22 expression after CD22 CAR T therapy, whole-exome sequencing and transcriptome sequencing of tumor cells revealed no mutations in the exon region of the CD22 gene and no new CD22 variant spliceosomes, with CD22 mRNA expression upregulated, suggesting that CD22 expression alterations occurred in a post-transcriptional regulatory process.