Four other ESTs, two from mammary tumor (AW211687 and AW212179) and two from a forelimb of E13 embryo (CJ049248 and CR514396) were identified upstream of the 5' end of Pdcd2, suggesting there may be a new gene transcribed from the same promoter as Pdcd2, but in the opposite orientation. Here, PDCD2 is linked to breast cancer.