Christopher Blackwell, Texas prisoner # 1757862, appeals the dismissal of his 42 U.S.C. § 1983 complaint for failure to state a claim upon which relief can be granted. The district court concluded that Blackwell’s claim that he was unconstitutionally denied release to mandatory supervision was barred by Heck v. Humphrey, 512 U.S. 477, 114 S.Ct. 2364, 129 L.Ed.2d 383 (1994). Blackwell has failed to assign as error or brief the basis of the district court’s dismissal. As such, he has abandoned review of the dismissal of his complaint for failure to state a claim. See Yohey v. Collins, 985 F.2d 222, 224-25 (5th *74 Cir. 1993); Brinkmann v. Dallas Cnty., Deputy Sheriff Abner, 813 F.2d 744, 748 (5th Cir. 1987).

AFFIRMED; MOTION TO FILE SUPPLEMENTAL BRIEF GRANTED.