I 
119TH CONGRESS 
1ST SESSION H. R. 2161 
To amend title 18, United States Code, to prohibit certain types of human- 
animal chimeras. 
IN THE HOUSE OF REPRESENTATIVES 
MARCH 14, 2025 
Mr. SMITH of New Jersey (for himself, Mr. HARRIS of Maryland, Mrs. MIL-
LER of Illinois, and Mr. ADERHOLT) introduced the following bill; which 
was referred to the Committee on the Judiciary 
A BILL 
To amend title 18, United States Code, to prohibit certain 
types of human-animal chimeras. 
Be it enacted by the Senate and House of Representa-
tives of the United States of America in Congress assembled, 
SECTION 1. SHORT TITLE. 
This Act may be cited as the ‘‘Human-Animal Chi-
mera Prohibition Act of 2025’’. 
SEC. 2. PROHIBITION ON CERTAIN HUMAN-ANIMAL CHI-
MERAS. 
Part I of title 18, United States Code, is amended 
by inserting after chapter 51 the following: 
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‘‘CHAPTER 52—CERTAIN TYPES OF 
HUMAN-ANIMAL CHIMERAS PROHIBITED 
‘‘Sec. 
‘‘1131. Definitions. 
‘‘1132. Prohibition on certain human-animal chimeras. 
‘‘§ 1131. Definitions 
‘‘In this chapter the following definitions apply: 
‘‘(1) PROHIBITED HUMAN-ANIMAL CHIMERA.— 
The 
term 
‘prohibited 
human-animal 
chimera’ 
means— 
‘‘(A) a human embryo into which a 
nonhuman cell or cells (or the component parts 
thereof) have been introduced to render the em-
bryo’s membership in the species Homo sapiens 
uncertain; 
‘‘(B) a human-animal embryo produced by 
fertilizing a human egg with nonhuman sperm; 
‘‘(C) a human-animal embryo produced by 
fertilizing a nonhuman egg with human sperm; 
‘‘(D) an embryo produced by introducing a 
nonhuman nucleus into a human egg; 
‘‘(E) an embryo produced by introducing a 
human nucleus into a nonhuman egg; 
‘‘(F) an embryo containing at least haploid 
sets of chromosomes from both a human and a 
nonhuman life form; 
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‘‘(G) a nonhuman life form engineered 
such that human gametes develop within the 
body of a nonhuman life form; 
‘‘(H) a nonhuman life form engineered 
such that it contains a human brain or a brain 
derived wholly or predominantly from human 
neural tissues; 
‘‘(I) a nonhuman life form engineered such 
that it exhibits human facial features or other 
bodily morphologies to resemble human fea-
tures; or 
‘‘(J) an embryo produced by mixing 
human and nonhuman cells, such that— 
‘‘(i) human gametes develop within 
the body of the resultant organism; 
‘‘(ii) it contains a human brain or a 
brain derived wholly or predominantly from 
human neural tissues; or 
‘‘(iii) it exhibits human facial features 
or other bodily morphologies to resemble 
human features. 
‘‘(2) HUMAN EMBRYO.—The term ‘human em-
bryo’ means an organism of the species Homo sapi-
ens during the earliest stages of development, from 
1 cell up to 8 weeks. 
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‘‘§ 1132. Prohibition on certain human-animal chi-
meras 
‘‘(a) IN GENERAL.—It shall be unlawful for any per-
son to knowingly, in or otherwise affecting interstate com-
merce— 
‘‘(1) create or attempt to create a prohibited 
human-animal chimera; 
‘‘(2) transfer or attempt to transfer a human 
embryo into a nonhuman womb; 
‘‘(3) transfer or attempt to transfer a non-
human embryo into a human womb; or 
‘‘(4) transport or receive for any purpose a pro-
hibited human-animal chimera. 
‘‘(b) PENALTIES.— 
‘‘(1) IN GENERAL.—Whoever violates subsection 
(a) shall be fined under this title, imprisoned not 
more than 10 years, or both. 
‘‘(2) CIVIL
PENALTY.—Whoever violates sub-
section (a) and derives pecuniary gain from such vio-
lation shall be subject to a civil fine of the greater 
of $1,000,000 and an amount equal to the amount 
of the gross gain multiplied by 2. 
‘‘(c) RULE OF CONSTRUCTION.—This section does 
not prohibit research involving the use of transgenic ani-
mal models containing human genes or transplantation of 
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human organs, tissues, or cells into recipient animals, if 
such activities are not prohibited under subsection (a).’’. 
SEC. 3. TECHNICAL AMENDMENT. 
The table of chapters for part I of title 18, United 
States Code, is amended by inserting after the item relat-
ing to chapter 51 the following: 
‘‘52. Certain types of human-animal chimeras prohibited.’’. 
Æ 
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