Additional analysis of TCGA data showed that normal colon tissues (n = 41) express similar or significantly lower mRNA levels of the receptors EphB1, EphB2, EphB3, and EphA4 compared to other normal tissues (n = 346; stomach n = 35; breast n = 92; lung n = 108; liver n = 50; melanoma n = 1; uterus n = 11; and prostate n = 49), but EphrinB2 and EphB4 mRNA levels are significantly higher (Fig. 1B). Here, EFNB2 is linked to melanoma.