This one comes to us from outside of the Fourth Circuit. For a discussion on the circuit split on this issue, see the blog post here.
Lopez v. Trani, No. 10-1088 (10th Cir. Dec. 6, 2010) (via 28 U.S.C. § 2254):
[August 18, 2011 Update: For the Ninth Circuit's en banc opinion on the matter, see Lee v. Lampert, No. 09-35276 (9th Cir. Aug. 2, 2011) (en banc))].
The Tenth Circuit held that a federal habeas petitioner seeking equitable tolling on the ground that he is actually innocent need only satisfy the actual-innocence standard of Schlup v. Delo, 513 U.S. 298 (1995), without also establishing cause for the late filing.