The principle articulated in Greenberg's Express--that the Court will not generally look behind a notice of deficiency--has been repeatedly upheld by courts, including the U.S. Court of Appeals for the Ninth Circuit. See Pasternak v. Commissioner, 990 F.2d 893, 898 (6th Cir. 1993), aff'g T.C. Memo. 1991-181; Ogiony v. Commissioner, 617 F.2d 14, 16-17 (2d Cir. 1980), aff'g and remanding T.C. Memo. 1979-32; Doyal v. Commissioner, 616 F.2d 1191, 1192 n.3 (10th Cir. 1980), aff'g T.C. Memo. 1978-307; Crowther v. Commissioner, 269 F.2d 292, 293 (9th Cir. 1959), aff'g on this issue 28 T.C. 1293 (1957). Respondent acknowledges that we have considered the administrative handling of a case when there is substantial evidence of unconstitutional conduct by respondent.