# List of keratins

The first sequences of keratins revealed that keratins could be grouped into two categories based on their sequence homologies. These two groups of keratins were named as type I and type II keratins. These two categories also represent the first two categories of the superfamily of intermediate filament proteins.
Keratins in this table are classified in the first two columns according to the nomenclature established in 2006. Other names previously used are listed in columns 3 and 4.

## Type I keratins
### Human epithelial keratins

| Protein name | Gene name | Other protein name | Other gene name |
| K9 | KRT9 | Ka9 | |
| K10 | KRT10 | Ka10 | |
| K12 | KRT12 | Ka12 | |
| K13 | KRT13 | Ka13 | |
| K14 | KRT14 | Ka14 | |
| K15 | KRT15 | Ka15 | |
| K16 | KRT16 | Ka16 | |
| K17 | KRT17 | Ka17 | |
| K18 | KRT18 | Ka18 | |
| K19 | KRT19 | Ka19 | |
| K20 | KRT20 | Ka20 | |
| K23 | KRT23 | Ka23 | |
| K24 | KRT24 | Ka24 | |
| K25 | KRT25 | Ka38, K25irs1, K10C, hIRSa1 | KRT25A |
| K26 | KRT26 | Ka39, K25irs2, K10D | |
| K27 | KRT27 | Ka40, K25irs3, K10B, hIRSa3.1 | |
| K28 | KRT28 | Ka41, K25irs4, hIRSa2 | |

### Human hair keratins

| Protein name | Gene name | Other protein name | Other gene name |
| K31 | KRT31 | Ka25, Ha1 | KRTHA1 |
| K32 | KRT32 | Ka26, Ha2 | KRTHA2 |
| K33a | KRT33A | Ka27, Ha3-I | KRTHA3A |
| K33b | KRT33B | Ka28, Ha3-II | KRTHA3B |
| K34 | KRT34 | Ka29, Ha4 | KRTHA4 |
| K35 | KRT35 | Ka30, Ha5 | KRTHA5 |
| K36 | KRT36 | Ka31, Ha6 | KRTHA6 |
| K37 | KRT37 | Ka32, Ha7 | KRTHA7 |
| K38 | KRT38 | Ka33, Ha8 | KRTHA8 |
| K39 | KRT39 | Ka35 | |
| K40 | KRT40 | Ka36 | |

### Nonhuman hair/epithelial keratins

| Protein name | Gene name | Other protein name | Other gene name |
| K41 chimp, gorilla, dog | KRT41 chimp, gorilla, dog; KRT41P man, horse | | φhHaA, Ka34P man |
| K42 mouse, rat | KRT42 mouse, rat; KRT42P man | Ka22 mouse, rat, K17n mouse, rat | |

### Human keratin pseudogenes

| Gene name | Other gene name |
| KRT221P | φhHaB |
| KRT222P | φKRTI, Ka21P |
| KRT223P | φKRTJ, Ka37P |

## Type II keratins
### Human epithelial keratin

| Protein name | Gene name | Other protein name | Other gene name |
| K1 | KRT1 | Kb1 | |
| K2 | KRT2 | Kb2, K2e | KRT2A |
| K3 | KRT3 | Kb3 | |
| K4 | KRT4 | Kb4 | |
| K5 | KRT5 | Kb5 | |
| K6a | KRT6A | Kb6 | |
| K6b | KRT6B | Kb10 | |
| K7 | KRT7 | Kb7 | |
| K8 | KRT8 | Kb8 | |
| K71 | KRT71 | Kb34, K6irs1 | |
| K72 | KRT72 | Kb35, K6irs2 | |
| K73 | KRT73 | Kb36, K6irs3 | |
| K74 | KRT74 | Kb37, K6irs4 | |
| K75 | KRT75 | Kb18, K6hf | |
| K76 | KRT76 | Kb9, K2p | KRT2B |
| K77 | KRT77 | Kb39, K1b | |
| K78 | KRT78 | Kb40, K5b | |
| K79 | KRT79 | Kb38, K6I | |
| K80 | KRT80 | Kb20 | |

### Human hair keratins

| Protein name | Gene name | Other protein name | Other gene name |
| K81 | KRT81 | Kb21, Hb1, K2.9 | KRTHB1 |
| K82 | KRT82 | Kb22, Hb2 | KRTHB2 |
| K83 | KRT83 | Kb23, Hb3, K2.10 | KRTHB3 |
| K84 | KRT84 | Kb24, Hb4 | KRTHB4 |
| K85 | KRT85 | Kb25, Hb5, K2.12 | KRTHB5 |
| K86 | KRT86 | Kb26, Hb6, K2.11 | KRTHB6 |

### Human keratin pseudogenes

| Gene name | Other gene name |
| KRT121P | φhHbD, Kb31P |
| KRT122P | φhHbC, Kb30P |
| KRT123P | φhHbB, Kb29P |
| KRT124P | φhHbA, Kb28P |
| KRT125P | φKRTH |
| KRT126P | φKRTG, Kb19P |
| KRT127P | φKRTF |
| KRT128P | φKRTE |