One example is ROPN1, which is an immediate neighborhood of FOXC1 and FOXA1. ROPN1, also known as ropporin, is a cancer-testis antigen[56] and a potential immune-therapeutic target for multiple myeloma as Chiriva-Internati et al. generated human leukocyte antigen class I-restricted cytotoxic lymphocytes to kill autologous multiple myeloma cells[57]. This evidence concerns the gene FOXC1 and AL amyloidosis.